Featuring a 3 zoned coil design, this mattress offers pressure relief and support where you need it, with a cool twist® gel memory foam that contours to your body—with upgrades available for even more cooling and comfort.Cool feel™ 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. Antimicrobial mattress protection - keeps your mattress fresh and clean from odor causing bacteria. This product protects the mattress but does not protect users against bacteria, viruses, germs or other disease organisms. Cool twist® gel memory foam - this breathable, gel-infused memory foam gently cradles your body while promoting enhanced airflow. 850 edition custom 3 zoned support coil system. This system of individually wrapped coils provides contouring, cradling support from edge-to-edge, minimizing the impact of your partner’s movements 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 TopMattress Type: InnerspringIncluded: 1 Mattress(es)Features: Wrapped Coils, Foam Layer, Antimicrobial, Temperature RegulatingAdditional Information: Conforms To Body, Suitable for Adjustable Bed FramesCoil Count: 493 CoilsManufacturer Warranty: 10 Year LimitedBed Size: TwinMeasurements: 76 Length/Inches, 12 Height/Inches, 40 Width/InchesMaximum Weight Limit: 1000 LbsBase Material: 90% Metal, 10% FoamComfort Type: Extra FirmCare: Spot CleanCertifications And Listings: Certipur-Us CertifiedMattress Height: 12"Country of Origin: Made in US Visit our Furniture & Mattress Customer Care Center for delivery options, protection plans and other services.Problem with an order or need help with a return? Our Furniture & Mattress Customer Service agents will be happy to help. Give us a call at 1-800-442-7902Don’t forget to print off your delivery checklist to avoid any delays or issues when delivering your item. Includes mattress only. Mattress plus box spring option also available. Serta Perfect Sleeper Cobalt Calm 12" Extra Firm - Mattress Only