Featuring 825 density coils, this supportive mattress offers zoned comfort and pressure relief where you need it-with upgrades available for even more cooling and comfort. Gel memory foam lumbar support band provides support for the lower back and hips   Serta® gel memory foam - serta® gel memory foam this unique gel memory foam contours to the body for cradling comfort and allows airflow to keep you cool and comfortable throughout the night.   Coolfeel™ fabric - a luxurious, breathable cover with a cool-to-the-touch sensation from technology that is plant-derived. Our biobased phase change material consists of 53% biobased content and is certified through the usda biopreferred® program.   825 edition custom support coil system - in addition to providing curve-hugging support and minimizing the impact of your partner's motions, this system of up to 825 individually wrapped coils features serta's bestedge® foam encasement technology - an extra-deep foam rail to help reduce edge roll-off and extend the sleep surface.   Proudly 100% usa assembled   Compatible with most frames, platforms and adjustable bases   We only use foam that is certipur-us certified Mattress Top Type: Tight Top Mattress Type: Innerspring Included: 1 Mattress(es), 1 Box Spring(s) Features: Breathable, Cooling, Wrapped Coils, Temperature Regulating, Foam Layer, Antimicrobial Additional Information: Conforms To Body Coil Count: 493 Coils Manufacturer Warranty: 10 Year Limited Bed Size: Twin Maximum Weight Limit: 1000 Lbs Base Material: 90% Metal, 10% Foam Comfort Type: Firm Mattress + Box Spring Measurements: 21 Depth/Inches, 40 Width/Inches, 70 Length/Inches Care: Spot Clean Certifications And Listings: Certipur-Us Certified Country of Origin: Made in US Set includes mattress plus box spring/foundation. King and Cal. King mattress sets feature 2-piece side-by-side foundations for easier navigation in tight spaces.