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Extra Firm
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On Sale
Mancini's Sleepworld Onyx Extra Firm Mattress 13"-Cal King
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In Stock
Mancini's Sleepworld Onyx Extra Firm Mattress 13"
Why this Mattress?
- Extra firm innerspring keeps your spine lifted all night
- Cooling stretch knit cover sleeps noticeably cooler
- Gel-infused memory foam takes the edge off pressure points
- Pocketed coil system moves with you, not against you
- Super high-density foam base built to last for years
Overview
Mancini's Sleepworld Onyx Extra Firm Mattress 13" · Cal King
The Mancini's Sleepworld Onyx Extra Firm Mattress 13" is an innerspring mattress built for back and stomach sleepers who need a solid, unyielding surface to keep their spine in line. If you've been waking up with your lower back complaining, this is the kind of extra firm mattress for back pain relief that stops that conversation before it starts. Thirteen inches of intentional construction give you real depth without any of the marshmallow sink that undermines your alignment overnight. Stop by any Mancini's Sleepworld location and let one of our sleep specialists put this right next to the alternatives so you can feel exactly what extra firm really means.
COMFORT AND FEEL: Extra firm with a cool, smooth surface and unyielding base support.
SIZE: This Cal King sized mattress is ideal for tall sleepers, couples who want maximum personal space, or anyone upgrading a spacious primary bedroom.
BEST SLEEP MATCH: Built for back and stomach sleepers who need firm support under the hips and lower back. The unyielding surface keeps the spine neutral so you stop waking up twisted.
BEST FOR: Ideal for sleepers who need strict spinal alignment, tend to run warm at night, or have struggled to find a mattress that holds its shape over time.
CONSTRUCTION SPECIFICATIONS: The heavyweight stretch knit cover is engineered to sleep cool and resist heat buildup. Gel-infused memory foam in the quilt layer softens contact without adding sinkage. Firm and extra firm high-density comfort foams deliver a controlled, non-compressive feel. The fabric-wrapped pocketed coil system reduces motion transfer between sleep partners. A shock-absorbing high-density base foam keeps the whole structure stable and resistant to early wear. CertiPUR-US certified.
SETUP AND COMPATIBILITY: Compatible with adjustable bases, platform frames, and standard box springs. Delivered flat with in-home professional setup available.
NOT A FIT FOR: Not recommended for side sleepers who need hip and shoulder cushioning, or anyone who prefers a plush or pressure-relieving feel.
YOUR SLEEP, BACKED BY US
Every mattress purchase at Mancini's Sleepworld comes with a 120-night comfort guarantee, so you have real time to know this is right for you. Add a premium mattress protector at checkout and you can extend that to a full 365 nights. We also back every purchase with our Rest Easy Promise, Best Price Guarantee, free next-day delivery, flexible financing, and in-home professional setup. Come try it in any of our stores before you buy.
- SleepMatch: red
Rest Easy Promise
Our promise to you.
- 365-Night Comfort Guarantee with purchase of a premium mattress protector
- Best Price Guarantee Find it lower and we’ll match it.
- Free Next-Day Delivery We’ll deliver to your door, set-up available.
- Double-Your-Warranty We match the manufacturer’s warranty.
Features
- SKU: BRK-ONY-6M-XF-25
- MPN: 25WICRAFEF_FP67
- GTIN: 810146419136
- Brand: Mancini's
- Collection: Sleepworld
- Type: Innerspring
- Mattress In A Box: No
- Firmness: Extra Firm
- Height: 13
- Length: 84
- Width: 72
- Shipping Height: 13
- Shipping Width: 84
- Shipping Length: 72
- Warranty: 10 Year
- Cover Material: Polyester Knit
- Quilting Layers: 3/4 Extra Firm Quilt Poly,3/4 H.D Gel Infused M - Foam
- Comfort Layers: 1'' Firm Support H.D. Foam ,1.5'' Extra Firm H.D. Support Foam
- Support System: 720 13.5 Ga. Pocketed coil, 1.0'' Shock Absorbing H.D. Base Foam
Specification
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Suitable For Adjustable Base: Yes
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Motion Separation: Yes
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Cooling Technology: Yes
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Edge Support: Yes