• Medium
  • On Sale

Why this Mattress?

  • Built to keep you cool all night long
  • Gel memory foam pulls heat away from the body
  • Fabric-wrapped coils absorb motion and hold the spine true
  • High-density support layers resist softening over time
  • CertiPUR-US certified foams, safe for the bedroom
Mancini's

Mancini's Sleepworld Onyx Medium Mattress 13"-Twin XL

Item No. BRK-ONY-3XM-MED-25
Delivery by Jul 13 to 94550
Price reduced from MSRP  $1,169.99 to Save 23% $899.99

Twin 3″ x 75″
Price reduced from MSRP  $1,039.99 to Save 23% $799.99
Twin XL 38″ x 80″
Price reduced from MSRP  $1,169.99 to Save 23% $899.99
Full 54″ x 75″
Price reduced from MSRP  $1,299.99 to Save 23% $999.99
Cal King 72″ x 84″
Price reduced from MSRP  $1,819.99 to Save 23% $1,399.99
Split Cal King 36″ x 84″
Price reduced from MSRP  $1,169.99 to Save 23% $899.99
Eastern King 76″ x 80″
Price reduced from MSRP  $1,819.99 to Save 23% $1,399.99
Queen 60″ x 80″
Price reduced from MSRP  $1,429.99 to Save 23% $1,099.99
Availability:
  • In Stock
Total $899.99
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Available to Try In-Store
Mancini's Sleepworld Livermore

Mancini's Sleepworld Onyx Medium Mattress 13"

Price reduced from MSRP  $1,169.99 to Save 23% $899.99
Price reduced from MSRP  $1,169.99 to Save 23% $899.99

Why this Mattress?

  • Built to keep you cool all night long
  • Gel memory foam pulls heat away from the body
  • Fabric-wrapped coils absorb motion and hold the spine true
  • High-density support layers resist softening over time
  • CertiPUR-US certified foams, safe for the bedroom

Overview

Mancini's Sleepworld Onyx Medium Mattress 13" Twin XL

The Mancini's Sleepworld Onyx Medium Mattress 13" is a hybrid mattress built for sleepers who run warm and want cradling comfort without losing the support that keeps them waking up pain-free. A heavyweight stretch knit quilt cover works with gel-infused memory foam underneath to move heat away from the body while the comfort foam layer softens the initial feel just enough to relieve pressure at the shoulders and hips. The pocketed coil system handles the rest, keeping the lumbar zone lifted through the night. Stop by any Mancini's Sleepworld location and our sleep specialists will put this next to every option in its class so you can feel the difference yourself.

COMFORT AND FEEL: Medium feel with a plush entry and firm coil rebound underneath.

SIZE: This Twin XL sized mattress is a natural fit for taller single sleepers, college students, and adjustable base setups in compact rooms.

BEST SLEEP MATCH: Best for back and side sleepers who need a medium firm mattress for back pain relief. The coil rebound keeps the spine aligned while the gel memory foam cushions pressure points at the hips and shoulders.

BEST FOR: Ideal for sleepers who run hot at night, need hip and shoulder pressure relief, or wake up stiff from a mattress that has lost its support.

CONSTRUCTION SPECIFICATIONS: The heavyweight stretch knit cover draws heat away the moment you lie down. Gel-infused memory foam in the quilt cushions pressure points without trapping warmth. Medium soft comfort foam beneath adds body-contouring depth. Fabric-wrapped pocketed coils absorb movement and deliver targeted lift. High-density base foam keeps the whole system from compressing out over time. Foams are CertiPUR-US certified.

SETUP AND COMPATIBILITY: Delivered flat with in-home professional setup included. Compatible with adjustable bases, platform frames, and box springs. No tools needed.

NOT A FIT FOR: Sleepers who prefer a fully soft, plush feel without any coil response, or those seeking an ultra-firm surface for stomach sleeping.

YOUR SLEEP, BACKED BY US

Every mattress purchase at Mancini's Sleepworld includes a 120-night comfort guarantee, and our Rest Easy Promise means you can try it in-store before you buy. Add a premium mattress protector at the time of purchase and your guarantee extends to a full 365 nights. You also get free next-day delivery, in-home professional setup, flexible financing, and our Best Price Guarantee. Our sleep specialists are here every step of the way.

  • SleepMatch: blue
Blue color code are mattresses of medium firm support. Most back sleepers and some side sleepers will find the beds measured as blue are best for them. Find Your Match
Couple relaxing on a mattress

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-3XM-MED-25
  • MPN: 25WICRAFM_FP33XL
  • GTIN: 810146419259
  • Brand: Mancini's
  • Collection: Sleepworld
  • Type: Innerspring
  • Mattress In A Box: No
  • Firmness: Medium
  • Height: 13
  • Length: 80
  • Width: 38
  • Shipping Height: 13
  • Shipping Width: 80
  • Shipping Length: 38
  • Warranty: 10 Year
  • Cover Material: Polyester Knit
  • Quilting Layers: 2 H.D. Super Soft Quilt Foam,3/4 H.D Gel Infused M - Foam
  • Comfort Layers: 1'' Med-Firm H.D. Foam + 1.5'' Extra Firm H.D. Support Foam
  • Support System: 8'' 840 Pocketed coil,1.0'' Shock Absorbing H.D. Base Foam

Specification

  • Suitable For Adjustable Base: Yes
  • Motion Separation: Yes
  • Cooling Technology: Yes
  • Edge Support: Yes