Powerblanket PBL20 Gas Cylinder Heater (Propane), 20 lb, Charcoal Gray Safely heats cylinder to an optimal 90  F / 32 C ( 10 F/5 C) 120 Volt, 120 Watts, 1.0 Amp Draw Also works on 30 and 40 Pound Gas Cylinder Tanks Eliminate unnecessary cylinder refills in cold weather Certified to UL/CSA/CE standards.Container Diameter 	 12.5 inches