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- Helix Core Midnight | Medium
Helix Core Midnight | Medium
Helix Core Midnight | Medium
Side Sleeper's Dream
7+ people bought
- Medium Comfort Level: A balanced feel that suits both back and side sleepers without being too soft or too firm.
- Instant Cooling Pillow Top: GlacioTex™ fabric delivers a refreshingly cool sleep surface right as you lie down.
- Contoured Ergonomics: Zoned foam layers cradle shoulders and reinforce hips and lower back for optimal alignment.
- Quiet Motion Isolation: Up to 1,000 individually wrapped coils absorb movement, keeping sleep disturbance to a minimum.
- Edge-to-Edge Stability: Reinforced coil edges ensure a supportive surface across the entire mattress.
Side
Back
Individual pocketed coil
Medium
Queen
$1,332
$999.95
King
$1,810
$1,358.95
Split King
$2,248
$1,686.90

Side Sleeper's Dream
Size guide
Size guide
Size | Dimensions | Weight |
---|---|---|
![]() Twin |
38" W × 75" L × 11.5" H | 65 LBS |
![]() Twin XL |
38"W x 80"L x 11.5"H | 67 LBS |
![]() Full |
54"W x 75"L x 11.5"H | 85 LBS |
![]() Queen |
60"W x 80"L x 11.5"H | 100 LBS |
![]() King |
76"W x 80"L x 11.5"H | 120 LBS |
![]() Split King |
38"W x 80"L x 11.5"H (Qty 2) | 134 LBS |
Bed frame options

Foundation | High Profile (9")
$130

Foundation | High Profile (9")
Strong 9" Steel Box Spring Base
- Heavy-Duty Steel Support: Semi-Flex® grid design outperforms wood foundations for strength and longevity.
- No Squeaks or Creaks: Welded truss construction stays quiet through the night.
- Non-Skid Top Fabric: Prevents mattress movement for a secure sleep surface.
- Ready to Use: No assembly required—just place and go.
- Compatible with All Mattresses: Designed to work with any type of mattress for full-body support.
Twin
$130
Twin XL
$150
Full
$160
Queen
$180
King
$300
In stock. Delivery by August 24

Adjustable Base | 1.0 Starter
$350

Adjustable Base | 1.0 Starter
Essential Comfort Base | Affordable Head Adjustability
- Head-Up Comfort: Effortlessly raise the head of your bed for better sleep, lounging, or nighttime reading.
- Simple Wired Control: Easy-to-use wired remote for smooth, no-fuss head elevation.
- Customizable Height: Three-in-one leg segments (3", 4", 5") to match your ideal bed height.
Twin XL
$350
Full
$400
Queen
$400
King
$600
Split King
$700
In stock. Delivery by August 24

Adjustable Base | 2.0 Basic
$650
$779

Adjustable Base | 2.0 Basic
Functional Flex Base | User-Friendly
- Custom Comfort: Easily adjust head and feet settings for personalized sleep and relaxation.
- Convenient Control: Wireless remote with custom presets and flashlight for easy, personalized adjustments.
- Flexible Design: Adjustable leg heights cater to various bed heights and aesthetic preferences.
Twin XL
$779
$650
Full
$999
$800
Queen
$999
$800
King
$1,299
$1,000
Split King
$1,558
$1,300
In stock. Delivery by August 24

Foundation | High Profile (9")
$150

Foundation | High Profile (9")
Strong 9" Steel Box Spring Base
- Heavy-Duty Steel Support: Semi-Flex® grid design outperforms wood foundations for strength and longevity.
- No Squeaks or Creaks: Welded truss construction stays quiet through the night.
- Non-Skid Top Fabric: Prevents mattress movement for a secure sleep surface.
- Ready to Use: No assembly required—just place and go.
- Compatible with All Mattresses: Designed to work with any type of mattress for full-body support.
Twin
$130
Twin XL
$150
Full
$160
Queen
$180
King
$300
In stock. Delivery by August 24

Adjustable Base | 1.0 Starter
$400

Adjustable Base | 1.0 Starter
Essential Comfort Base | Affordable Head Adjustability
- Head-Up Comfort: Effortlessly raise the head of your bed for better sleep, lounging, or nighttime reading.
- Simple Wired Control: Easy-to-use wired remote for smooth, no-fuss head elevation.
- Customizable Height: Three-in-one leg segments (3", 4", 5") to match your ideal bed height.
Twin XL
$350
Full
$400
Queen
$400
King
$600
Split King
$700
In stock. Delivery by August 24

Adjustable Base | 2.0 Basic
$800
$999

Adjustable Base | 2.0 Basic
Functional Flex Base | User-Friendly
- Custom Comfort: Easily adjust head and feet settings for personalized sleep and relaxation.
- Convenient Control: Wireless remote with custom presets and flashlight for easy, personalized adjustments.
- Flexible Design: Adjustable leg heights cater to various bed heights and aesthetic preferences.
Twin XL
$779
$650
Full
$999
$800
Queen
$999
$800
King
$1,299
$1,000
Split King
$1,558
$1,300
In stock. Delivery by August 24

Foundation | High Profile (9")
$160

Foundation | High Profile (9")
Strong 9" Steel Box Spring Base
- Heavy-Duty Steel Support: Semi-Flex® grid design outperforms wood foundations for strength and longevity.
- No Squeaks or Creaks: Welded truss construction stays quiet through the night.
- Non-Skid Top Fabric: Prevents mattress movement for a secure sleep surface.
- Ready to Use: No assembly required—just place and go.
- Compatible with All Mattresses: Designed to work with any type of mattress for full-body support.
Twin
$130
Twin XL
$150
Full
$160
Queen
$180
King
$300
In stock. Delivery by August 24

Adjustable Base | 1.0 Starter
$400

Adjustable Base | 1.0 Starter
Essential Comfort Base | Affordable Head Adjustability
- Head-Up Comfort: Effortlessly raise the head of your bed for better sleep, lounging, or nighttime reading.
- Simple Wired Control: Easy-to-use wired remote for smooth, no-fuss head elevation.
- Customizable Height: Three-in-one leg segments (3", 4", 5") to match your ideal bed height.
Twin XL
$350
Full
$400
Queen
$400
King
$600
Split King
$700
In stock. Delivery by August 24

Adjustable Base | 2.0 Basic
$800
$999

Adjustable Base | 2.0 Basic
Functional Flex Base | User-Friendly
- Custom Comfort: Easily adjust head and feet settings for personalized sleep and relaxation.
- Convenient Control: Wireless remote with custom presets and flashlight for easy, personalized adjustments.
- Flexible Design: Adjustable leg heights cater to various bed heights and aesthetic preferences.
Twin XL
$779
$650
Full
$999
$800
Queen
$999
$800
King
$1,299
$1,000
Split King
$1,558
$1,300
In stock. Delivery by August 24

Foundation | High Profile (9")
$180

Foundation | High Profile (9")
Strong 9" Steel Box Spring Base
- Heavy-Duty Steel Support: Semi-Flex® grid design outperforms wood foundations for strength and longevity.
- No Squeaks or Creaks: Welded truss construction stays quiet through the night.
- Non-Skid Top Fabric: Prevents mattress movement for a secure sleep surface.
- Ready to Use: No assembly required—just place and go.
- Compatible with All Mattresses: Designed to work with any type of mattress for full-body support.
Twin
$130
Twin XL
$150
Full
$160
Queen
$180
King
$300
In stock. Delivery by August 24

Adjustable Base | 1.0 Starter
$600

Adjustable Base | 1.0 Starter
Essential Comfort Base | Affordable Head Adjustability
- Head-Up Comfort: Effortlessly raise the head of your bed for better sleep, lounging, or nighttime reading.
- Simple Wired Control: Easy-to-use wired remote for smooth, no-fuss head elevation.
- Customizable Height: Three-in-one leg segments (3", 4", 5") to match your ideal bed height.
Twin XL
$350
Full
$400
Queen
$400
King
$600
Split King
$700
In stock. Delivery by August 24

Adjustable Base | 2.0 Basic
$1,000
$1,299

Adjustable Base | 2.0 Basic
Functional Flex Base | User-Friendly
- Custom Comfort: Easily adjust head and feet settings for personalized sleep and relaxation.
- Convenient Control: Wireless remote with custom presets and flashlight for easy, personalized adjustments.
- Flexible Design: Adjustable leg heights cater to various bed heights and aesthetic preferences.
Twin XL
$779
$650
Full
$999
$800
Queen
$999
$800
King
$1,299
$1,000
Split King
$1,558
$1,300
In stock. Delivery by August 24

Foundation | High Profile (9")
$300

Foundation | High Profile (9")
Strong 9" Steel Box Spring Base
- Heavy-Duty Steel Support: Semi-Flex® grid design outperforms wood foundations for strength and longevity.
- No Squeaks or Creaks: Welded truss construction stays quiet through the night.
- Non-Skid Top Fabric: Prevents mattress movement for a secure sleep surface.
- Ready to Use: No assembly required—just place and go.
- Compatible with All Mattresses: Designed to work with any type of mattress for full-body support.
Twin
$130
Twin XL
$150
Full
$160
Queen
$180
King
$300
In stock. Delivery by August 24

Adjustable Base | 1.0 Starter
$700

Adjustable Base | 1.0 Starter
Essential Comfort Base | Affordable Head Adjustability
- Head-Up Comfort: Effortlessly raise the head of your bed for better sleep, lounging, or nighttime reading.
- Simple Wired Control: Easy-to-use wired remote for smooth, no-fuss head elevation.
- Customizable Height: Three-in-one leg segments (3", 4", 5") to match your ideal bed height.
Twin XL
$350
Full
$400
Queen
$400
King
$600
Split King
$700
In stock. Delivery by August 24

Adjustable Base | 2.0 Basic
$1,300
$1,558

Adjustable Base | 2.0 Basic
Functional Flex Base | User-Friendly
- Custom Comfort: Easily adjust head and feet settings for personalized sleep and relaxation.
- Convenient Control: Wireless remote with custom presets and flashlight for easy, personalized adjustments.
- Flexible Design: Adjustable leg heights cater to various bed heights and aesthetic preferences.
Twin XL
$779
$650
Full
$999
$800
Queen
$999
$800
King
$1,299
$1,000
Split King
$1,558
$1,300
In stock. Delivery by August 24
In stock. Delivery by August 25
100-Night Trial
Free One-Day Delivery
Lifetime Warranty
- Expertly handled by our dedicated Mattress King Delivery Crew.
- Secure delivery right to your doorstep or garage, mirroring the convenience of services like FedEx, UPS, or Amazon.
Upgrade to our comprehensive service that includes everything in the Free Delivery, plus:
- Personalized delivery and setup in your preferred room.
- Safe removal of your old mattress and box spring, if required.
- Eco-friendly disposal of all packaging materials.
Exclusively Serving Oklahoma- For detailed delivery information, please visit here
- Mattress King Oklahoma City (208 S Portland Ave, Oklahoma City)
- Mattress King Stillwater (511 S Main St, Stillwater)
- Mattress King Lawton-North (1318 NW Sheridan Rd, Lawton)
Materials
Construction of Mattress:
6 Layer Design, 11.5" Profile
- 0.75″ Gel‑Infused Foam quilted into GlacioTex™ Cooling Cover
- 1.5″ Gel‑Infused Memory Foam Layer
- 1″ Soft Responsive Foam Layer
- 1″ Support Responsive Foam Layer
- Up to 1,000 Individually Wrapped Coils with Reinforced Edge Support
- 0.5″ Durable Base Foam
- Shift-Resistant Lower Cove
Basic Care: Spot clean with a mild detergent, such as upholstery cleaner. We highly recommend using a waterproof mattress protector to ensure the longevity of your mattress.
Certifications
All foams meet CertiPUR-US® standards for content, emissions, and durability, and are analyzed by independent, accredited testing laboratories.
Protected by a chemical-free and fiberglass-free fire barrier meeting 16 CFR 1633 and 16 CFR 1632 compliance
is a certification program administered by a nonprofit organization.
- Made without ozone depleters
- Made without PBDEs or the following Tris flame retardants: TCEP, TDBPP, TDCPP or TEPA
- Made without mercury, lead, and other heavy metals
- Made without formaldehyde
- Made without phthalates regulated by the Consumer Product Safety Commission
- Low VOC (Volatile Organic Compound) emissions for indoor air quality (less than 0.5 parts per million)
Warranty
Lifetime Limited Warranty
If defects in materials or workmanship arise, Helix Sleep will repair or replace your mattress for as long as you own it. Pair with Mattress King's 100-night risk-free trial for total peace of mind.
View full warranty details here
Where it’s made
American Craftsmanship: Made in Arizona
Expert Assistance Awaits
Get expert advice from our sleep specialists to ensure your best night’s sleep.
OR
Prefer a Personal Touch? Book Your In-Store Visit to discover mattresses and sleep essentials customized for your comfort.






Medium Comfort Meets Cooling & Contoured Support
The Helix Core Midnight combines a cooling GlacioTex™ pillow-top with adaptive gel memory foam and responsive transition layers. Zoned for ergonomic alignment and topped with breathable design, this hybrid supports your body where needed and keeps you cool. Individually wrapped coils offer responsive support and excellent motion control, while reinforced edges extend usable sleeping area for stability and comfort.
The Helix Core Midnight combines a cooling GlacioTex™ pillow-top with adaptive gel memory foam and responsive transition layers. Zoned for ergonomic alignment and topped with breathable design, this hybrid supports your body where needed and keeps you cool. Individually wrapped coils offer responsive support and excellent motion control, while reinforced edges extend usable sleeping area for stability and comfort.

Firmness Scale
1-3
3-4
4-6
6-8
8-9
9-10
Plush
Medium-Plush
Medium
Medium-Firm
Firm
Extra-firm
Support
Support ensures a mattress keeps its shape under your body weight, providing essential spinal alignment. Ideal for partners or larger body types, it evenly distributes weight for lasting structural integrity.
Learn more
Low
Medium
High
Pressure Relief
Basic
Average
Advanced
Air Circulation
Air circulation regulates temperature for comfortable sleep. Upgraded mattresses with special fabrics and foams offer superior cooling, ensuring a more restful experience compared to standard options.
Good
Better
Best
You may also like...

Nectar Classic Hybrid Mattress | Medium
$469.95
$799.00or as low as $117/month

Nectar Classic Memory Foam | Medium-Firm
$349.95
$699.00or as low as $87/month

Midnight | Medium
$499.95
$574.00or as low as $124/month

Sapphire | Medium
$449.00
or as low as $112/month
Frequently bought together...

Foundation | High Profile (9")
$130.00
or as low as $32/month

Monster Bed Frame
$89.95
or as low as $22/month

Adjustable Base | 2.0 Basic
$650.00
$779.00or as low as $162/month

Premium Smooth Waterproof Mattress Protector
$45.95
or as low as $11/month
Frequently Asked Questions
Who is the Helix Core Midnight best for?
This mattress is a great fit for back and side sleepers seeking medium support—neither too soft nor too firm. It offers balanced comfort that caters well to combination sleepers too.
How well does it stay cool?
Very well. The GlacioTex™ pillow top provides cooling to the touch, while gel-infused memory foam and breathable coils help regulate sleep temperature effectively. Several independent reviews rate its cooling performance highly
I've seen Helix online. What's the benefit of buying from Mattress King?
Buying from Mattress King gives you several key advantages. You can come into one of our 6 Oklahoma showrooms to try the Helix Midnight in person before you buy. You'll get our fast, 1-day local delivery instead of waiting for a box to ship. Most importantly, you get the dedicated service of a local team and the peace of mind of our 100-Night Comfort Guarantee, which allows for an easy, in-store exchange if needed.
Do you offer delivery and old mattress haul-away services?
Yes, at Mattress King, we provide convenient delivery services across Oklahoma. We pride ourselves on offering fast, one-day delivery options. For those who opt for our upgraded delivery service, priced at $99, we not only deliver but also set up your new mattress and haul away your old one. In addition to this, we offer a free delivery option that includes doorstep drop-off, similar to services provided by FedEx and Amazon. This option is great for those who prefer a contactless delivery to their front porch or door. For a comprehensive understanding of our delivery services and to find the best option for your needs, please visit our delivery information page here.
Do you offer financing options?
At Mattress King, we offer a variety of financing options to fit your budget. Our financing partners include Synchrony, Affirm, and Snap Finance, each offering distinct plans to accommodate different financial needs.
Synchrony: For those with good credit, Synchrony provides a 12-month plan with 0% interest, helping you manage payments without additional costs.
Affirm: Affirm offers flexibility with interest rates ranging from 0% to 36%. They provide three payment term options, allowing you to choose a plan that best suits your budget.
Snap Finance: Ideal for those who might not have a strong credit history. Snap Finance considers other factors like a steady income and an active checking account. They offer a 100-day cash option and operate on a lease-to-own basis.
Each of these options is designed to make your mattress purchase more manageable financially. You can explore these options and apply directly to find the one that aligns with your financial situation.
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