Heated Mattress Pads/Covers fit directly on your Mattress. Heat stays in your bed instead of rising into the room. Bed Warmers keep your bed warm and dry. Available in X-Long sizes for Adjustable and Flat Beds. 12 Volt units for Semi-Sleepers, RV, and Campers are currently OUT OF STOCK until further notice. We apologize for the inconvenience. 115V Heated Mattress Pads in stock.