Other Components Draft-O-Stat® Draft Control Draft-O-Stat has for many years been the standard barometric draft control mechanism for boilers, furnaces, oil burners and stokers. Millions of successful installations on domestic, commercial and industrial heating equipment have established its leadership in the field. Current Sensing Relay Model A50 (24 Volt) For interfacing humidifiers with all types of forced air furnaces and air conditioning equipment. The Model A50 (24 volt) Current Sensing Relay has been designed for interfacing humidifiers with most heating and cooling systems. This type of relay is more reliable and inexpensive than using sail switches, pressure switches or other types of relays. Current Sensing Relay Model A51 (120 Volt) For interfacing humidifiers or electronic air cleaners with all types of forced air furnaces and air conditioning equipment. The Model A51 (120 volt) Current Sensing Relay has been designed for interfacing humidifiers or air cleaners with most heating and cooling systems. This type of relay is more reliable and inexpensive than using sail switches, pressure switches or other types of relays. Sparklite® Electronic Ignition Systems Specially designed and engineered to fit most gas heating systems. Cycling pilot saves energy and money year-round! The Gas Saver Retrofit package makes the gas ignition system on your furnace or boiler comparable to the one on a new furnace. Can be used on equipment up to 400,000 B.T.U./Hr. Thermo-Hygrometer Fast response, high accuracy, reads temperature and humidity simultaneously. Versatile, portable and easy to use. Fits right in your shirt pocket!