Sleepyhead Twin XL 3 Inch Premium Gel Mattress Topper – Gel Memory Foam Mattress Topper for College Dorm Beds – Cooling, Pressure Relief, Washable Cover, CertiPUR-US Certified (XL Twin 3") Twin XL 3-Inch Cooling Gel is up for auction in Home & Kitchen. The current bid is $12.50, 97% below the $399.00 MSRP, in New/Like New condition. This auction has ended — similar items appear in live auctions regularly.