Check the listing for details. Pottery Barn SLEEPSMART 37.5 TEMPERATURE REGULATING 550fp Down Duvet Insert King. Color: White, Condition: New with tags. Listed at 299.00 USD. Pottery Barn Sleepsmart 37.5 Technology Temperature Regulating 550FP Down Blend Duvet Insert ~King/California King New with Tag PB describes: Our exclusive SleepSmart™ bedding continuously adjusts to help maintain a climate of personal comfort at the ideal temperature of 37.5° Celsius all night long. Paired with the softness of down, this duvet insert gives you comfort and warmth that'll leave you waking up rested and refreshed. Shell is woven of 80% cotton and 20% 37.5° performance polyester.Innovative blend of 550 fill power White Down and 37.5° fiber in the fill provides enhanced thermoregulation.37.5° activated carbon particles absorb odor molecules to keep your bedding smelling fresh.Sleep smart™ 37.5™ technology uses naturally derived fibers that work continuously to trap heat when cold or evaporate excess humidity when warm before sweat can form.Sleep smart™ is designed to work as a total system; it’s performance increases with additional Sleep smart™ layers.Sleep smart™ high-performance properties last the life of the product.Double needle stitch sewn through box quilting prevents fill from shifting & has corner loops for easy attachment to your duvet cover.Allergen barrier weave is breathable yet resists allergens from entering into your bedding.230 thread count.As you sleep, temperature and humidity build-up and become trapped in your sleep environment or microclimate. This is where you start to feel overheated and uncomfortable and eventually disrupt your rest.Body heat-activated performance. Comfort personalized to each sleeper's need for warmth, so you stay asleep longer.Imported. King/California King Duvet Insert: 94" l x 114" w Pet & Smoke freeShips within 1 business dayThank you