This ultra-quiet heater is perfect for boats, homes and offices. Versatility and simplicity with three heat settings-1500W (5200Btu), 900W (3120Btu) and “energy saver” 600W (2080Btu), which draws just 5A. Adjustable thermostat control keeps you comfortable. Antifreeze setting automatically turns on when temperature drops to 38°F. Overheat protector will not clog with dust or dirt.