Go beyond traditional bedding. The Core Mattress Pad features two layers of NASA-approved temperature regulating technology. Built for spacesuits but optimized for your bed, this Outlast technology absorbs heat when you're too hot and releases it back when you're too cold, while the top layer provides additional temperature-regulation.Bedding basics that keep you and your mattress at the perfect sleeping temperature. To ensure our Core Mattress Pad helps even the hottest sleepers stay cool and comfortable all night long, we integrated extra temperature regulating technology into the top cover for maximum heat absorption.Features300 thread count - 40% NASA-approved Outlast viscose / 60% cotton top cover for peak breathability and temperature-regulationProprietary Outlast lining fabric for maximum heat management and added comfortOeko-Tex Standard 100 Certified TechnologyDesigned to be used underneath your fitted sheetFits any mattress up to 20'Easy to Care For: Just throw it in your home washing machineTechnology: Traditional bedding and moisture wicking technologies react to changes in your body temperature while you sleep. Slumber Cloud® is doing something different.Slumber Cloud® Bedding utilizes Outlast technology for a unmatched approach to temperature regulation. Outlast technology is proactive, not reactive. As your body temperature increases during sleep, Outlast technology stores that heat to keep you cool, and then releases it as you cool down...keeping you feeling just right.Materials: Our premium lining fabric takes a proactive approach by employing active temperature control properties, versus other "cooling" bedding that is moisture-wicking and simply reactive.Benefits: Outlast materials improve comfort for: Anyone looking for a more comfortable night's sleep - they'll sleep cooler and more comfortably. Sleepers who struggle with hot flashes and night sweats - proactive temperature regulation means they'll sleep cooler and drier and wake up feeling refreshed. Thermally incompatible couples - individuals can sleep at their own ideal temperature.Research: We pass on everything we learn to our customers. From sleep studies to new technologies, we want to help you make informed decisions about your sleep.Size GuideTwin: 39 x 75Twin XL: 39 x 80Full: 54 x 75Queen: 60 x 80King: 78 x 80Cal-King: 72 x 84Split-King: 2 x 39 x 80® Registered Trademark of Global Web Horizons LLC dba Slumber Cloud Slumber Cloud ® Outlast Core Mattress Pad, White - Cal-King