Memory Foam COOLING 3-INCH TWIN XL TOPPER: TEMPUR-Adapt + Cooling topper is ideal for getting the perfect night’s sleep on the go or at home. 79. 5 x 37. 8 x 2. 9 size perfectly fits a twin XL size mattress. SOFTEST TEMPUR MATERIAL: 3-inches of exclusive TEMPUR-ES Material precisely adapts to your unique shape, weight and temperature. Instantly enhances the comfort and support of any mattress.