The Ultra Heat RV Holding Tank Heater used to prevent freeze-ups in holding and freshwater storage tanks. Specifications•Compatibility: Heats Up To A 40 Gallon Capacity Tank•Mounting Type: Peel And Stick•Voltage Rating: 13.5 Volt•Ampere Rating: 9.9 Amp•Length (IN):20 Inch•Width (IN):12 Inch Features A Easy Peel-N-Stick Backing Using The Proprietary Adhesive Formula The Adhesive Applied Gives A Stronger Molecular Concentration, Far Superior To The Secondary Adhesion Process Most Commonly Used | Ultra Heat RV Holding Tank Heater, 20"L x 12"W, 40 Gallon