Universal electronic fan timer made of carbon steel for long lasting durability. Control provides central wiring point for most electrical components in furnace. Monitors thermostat for heat, cool and fan demand for gas. Replace all existing honeywell st9120, st9101, st9141 and st9160 models with the universal electronic fan timer. Integrates control of all combustion blower and circulating fan operations in gas warm air appliance. Replaceable fuse and dip switch with selectable heat and cool delay for added flexibility. Diagnostic led and continuous eac and hum terminal connections. Hertz is 60 . Gas valve is -40-150f .