The INF Input Regulator is considered an “infinite switch”. It operates with a bi-metal contact. It pulses the heater on and off as the internal contact heats up; as the contact cools, it closes, and the heater comes back on. It is considered a coarse form of control and is commonly used for electric heaters and stoves. INF20 Maximum Load – 3000 watts at 208V and 3600 watts at 240V. 15 amp max.