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Serta Perfect Sleeper X™ Quilted Knox Firm Mattress

by Serta
Original price $999.99 - Original price $1,899.99
Original price $1,549.99
$999.99
$999.99 - $1,899.99
Current price $999.99
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Free Curbside Shipping: 2 Weeks
White Glove Delivery: 3 Weeks
White Glove Delivery + Removal: 3 Weeks

Serta Perfect Sleeper X™ Quilted Knox Firm Mattress

Experience premium support and perfect sleep with the Serta Perfect Sleeper X™ Quilted Knox Firm Mattress. This 13.5-inch quilted hybrid mattress combines advanced support zones, graphite-infused memory foam, and cooling technology to promote full-body alignment and provide a restorative night's sleep.

Key Features:

  • Comfort Level: Firm feel, ideal for back and stomach sleepers seeking substantial support.
  • Support System: 5 ZoneResponse™ Design combines zoned coils and contouring memory foam for full-body spinal alignment, offering comfort and support where you need it most.
  • Pressure Relief: 1" Perfect Conform™ Memory Foam, graphite-infused to provide targeted pressure relief and redistribute heat away from the body.
  • Cooling Technology: CoolFeel™ System keeps you comfortable throughout the night by promoting a cooler sleep environment.
  • Motion Isolation: Designed to minimize the impact of partner movement, ensuring undisturbed rest.
  • Profile Height: 13.5 inches, offering a substantial and supportive sleep surface.

Materials & Construction:

  • 5 ZoneResponse™ Design: Combines zoned coils and contouring memory foam for full-body spinal alignment, providing comfort and support where needed most.
  • Perfect Conform™ Memory Foam: 1-inch layer that adapts to your body's curves, alleviating pressure points for enhanced comfort.
  • Graphite-Infused Memory Foam: Helps redistribute heat away from the body, maintaining an optimal sleep temperature.
  • CoolFeel™ System: Keeps you comfortable throughout the night by promoting a cooler sleep environment.
  • CertiPUR-US® Certified: Foams are tested and free from harmful chemicals and gases, ensuring safety and eco-friendliness.

Care Instructions:

  • Use a mattress protector to safeguard against stains and spills, enhancing the overall health and lifespan of your mattress.
  • Avoid applying liquids directly to the mattress; for cleaning, apply baking soda to the soiled area, let it stand for about 15 minutes, then vacuum. Repeat as needed.
  • Air out the product as much as possible to maintain freshness.

Compatible with most frames, including traditional frames, box springs, platform frames, slatted frames, bunky boards, and adjustable frames.

Additional Information:

  • Warranty: Backed by Serta’s 10-year limited warranty for peace of mind.
  • Sizes Available: Twin XL, Full, Queen, King, and California King.
  • 120-Day In-Home Trial: Experience the mattress in your home for up to 120 days; if not completely satisfied, you can exchange or return it for a refund.

10 Year Limited Warranty

Serta® mattresses or foundations used with proper support are protected by a 10 year limited manufacturer’s warranty. Serta products are warrantied against manufacturing defects in workmanship and material (excluding covers and handles, except for handles on iSeries and equivalent level mattresses).

Exclusions

    Comfort Preference
  • Bedding sold “as is”, or floor samples, or bedding purchased from second hand parties, non-retail establishments or received as a promotional item.
  • Bedding height
  • Corner guards
  • Bent perimeter border rods due to moving or bending the sleep set for innerspring models
  • Replacement of another piece in a sleep set unless it is also defective
  • Damage of the mattress or foundation due to misuse or abuse
  • Mattress damage due to an inappropriate foundation or when an incorrect bed frame is used
  • Sheet fit
  • Fabric Stains, soiling, fluid penetration, tears or burns
  • Adjustable foundations (see owner’s manual for details on warranty coverage)
  • Mattress fabric (except as noted in the Warranty Coverage Detail section for an All Foam mattress)
  • Zippered mattress cover damage due to improper care including removal of cover
  • Normal change in softness and recovery time associated with memory foam and latex materials over time. This does not affect the pressure relieving qualities of these materials.
  • Body impressions in the mattress that measure less than ¾" for all smooth top (non-quilted) hybrid mattresses and All Foam model mattresses.
  • Sagging in the mattress that measure less than less than ¾" for all smooth top (non-quilted) hybrid mattresses and All Foam model mattresses.

Term

The warranty coverage runs from the original date of purchase. Replacement of the mattress or foundation does not extend its limited warranty or begin a new limited warranty period. Your warranty period is based on the code printed on your white law label as indicated on the Warranty Code Chart. The duration of any applicable implied warranties, including but not limited to the implied warranties of merchantability and fitness, shall not exceed the term of this limited warranty. (Some states do not allow limitations on how long an implied warranty lasts, so this limitation may not apply to you.) Serta® shall not be liable for incidental or consequential damages that result from the use of your Serta® product. (Some states do not allow the exclusion or limitation of incidental or consequential damages, so this exclusion may not apply to you.) No expressed or implied warranties are extended to persons who purchase the product from anyone other than Serta Simmons Bedding Company or its authorized dealers, and all warranties to such persons, including the implied warranties of merchantability and fitness, are hereby excluded.

Service

If your Serta® mattress or foundation fails due to a manufacturing defect, the exclusive remedy under this warranty will be replacement of the defective product in the U.S., Puerto Rico or U.S. Virgin Islands. If the Serta® product you purchased is discontinued at the time of replacement, a current model of comparable quality and value will be selected. To receive service under the terms of this warranty contact your original Serta® dealer. If your original Serta® dealer is no longer in business or you have moved outside the service area, please contact Serta Customer Service at 1-888-55-SERTA (1-888-557-3782) between the hours of 9am to 5pm EST Monday - Friday. A copy of original bill of sale is needed to determine original date of purchase. Model name label and law label must be provided to identify the bedding and validate this warranty.

Your Rights Under State Law

This warranty gives you specific rights, and you may have other rights, which vary from state to state. This warranty is extended only to the original purchaser from Serta Simmons Bedding Company or its authorized dealers.

Why Buy Serta Online?

10-YEAR LIMITED WARRANTY

You should be able to rely on the quality of your rest night after night. That’s why every Serta® mattress is backed by Serta’s 10-year limited warranty.

DESIGNED & BUILT IN THE USA

All Serta mattresses are designed and assembled in the USA, leveraging our 85 years of manufacturing expertise.

CERTIPUR-US® CERTIFIED

Rest easy knowing Serta uses only CertiPUR-US® Certified Polyurethane Foam.

Perfect Sleeper X Quilted FAQS

This mattress pairs a classic quilted feel with hybrid support: five body zones for alignment, an 850-coil density system for contouring support and motion isolation, 1″ Perfect Conform™ Memory Foam for pressure relief, and a cool-to-the-touch CoolFeel™ fabric cover. Memory foam and cooling upgrades are available on select models.

The support core is zoned so firmness varies by area to promote spinal alignment: more support where your body naturally curves (for example lower back and upper thigh) and appropriate comfort where you make the most contact (shoulders, hips, and lower legs).

Level 1 delivers the quilted hybrid foundation: zoned coils, 1″ Perfect Conform™ Memory Foam, and the CoolFeel™ cover. Level 2 adds up to about 5″ of professional-grade latex-style foam for extra responsive comfort plus a more advanced cooling story—choose the level that matches your budget and how much contouring versus “lift” you want.

Comfort levels vary by level: Level 1 includes options such as Extra Firm, Firm, Plush, Enhanced Plush, and Medium Pillow Top; Level 2 includes options such as Medium, Firm Pillow Top, and Plush Pillow Top. Sizes typically include Twin XL, Full, Queen, King, and California King—confirm availability for the exact model you are viewing.

Yes. The quilted top is paired with a cool-to-the-touch cover made with CoolFeel™ fabric, and select builds add cooling gel swirled into premium memory foam for airflow, heat dissipation, and contouring comfort.

An 850-coil density system delivers cushioning, cradling support and helps limit motion transfer from a partner. BestEdge® Foam Encasement adds a deep foam rail to reduce edge roll-off and extend the usable sleep surface.

When purchased direct from Serta.com, many shoppers receive a 100-night in-home trial and free shipping and returns, plus a 10-year limited warranty against qualifying manufacturing defects. Policies can differ by retailer—always verify at checkout.

It is compatible with most setups, including traditional frames, box springs, platforms, slatted foundations, bunky boards, and adjustable bases—use a supportive foundation that matches the manufacturer’s spacing and weight guidelines.

According to Serta, the Perfect Sleeper X line does not contain fiberglass.

Use a mattress protector to guard against stains and extend mattress life. Do not soak the mattress or apply liquids directly; for spots, sprinkle baking soda, wait about 15 minutes, vacuum, and repeat as needed, and air the bed out when possible. Foams are CertiPUR-US® certified for tested content.