The DiversiTech® HMR-130 Bi-metal Manual Reset Fire Stat is used as a manual reset. When temperature condition is met, the device opens. The manual reset can only be reset after proper cool-down of the switch. The HMR-130 is a popular fire stat in ducted air distribution systems. Should temperatures in the duct exceed 130F, the switch opens, shutting down the whole system so no fire or smoke can be spread by the fan.