The Robinair 13184 heater blanket speeds charging by maintaining a constant temperature, thus creating a positive pressure between the refrigerant tank and the A/C system. It fits 30 and 50 pound refrigerant tanks. Thermostat is set at 125 degrees F (55 degree C). Thermal cut-off switch protects against overheating. 300 watts, 2.6 amps. Heater blanket 220 Volts - 240 Volts 50 Hz with internal IEC receptacle.