The KM-99 GY is a part of the MASZCZYK (Manual Anti-fire Alarm System) family of fire safety products. It is an external surface-mounted fire alarm switch which is designed to be used on masonry walls. It features a single pole, normally open switch that activates a relay upon activation. The relay can be used to trigger an alarm, such as a strobe light, wireless alarm, or siren. The KM-99 GY is a robust and reliable part of the MASZCZYK fire safety system and is suitable for both indoor and outdoor use.