Indoor safe propane heater with high, medium, and low settings. Features low oxygen and tip over safety shutoffs. Heats up to 400 sq. ft. using two 1 lb. disposable propane cylinders or a 20 lb. cylinder (must use hose assembly ? SOLD SEPARATELY). Heater fan operates on 4 D cell batteries (sold separately) or AC adapter. Sales restricted in Massachussetts and Cananda.