Sunbeam Biddeford Twin XL Quilted Electric Heated Mattress Pad with Corner Straps Polyester-blend Auto Shut Off: Pad Turns Off After 10 Hours; Includes One Analog Controllers 10 Personal Heat Settings; Therapeutic Warmth 80% Polyester and 20% Cotton; Generously Filled Quilted Top Pad is Held In Place With Four Elastic Corner Straps: Straps Fit Up to 21" Mattress Energy Saving; Machine Washable; Dimensions: 39" x 80"