The single-action manual fire alarm box (Model MS-151) is intended for use with all Siemens – Fire Safety low-voltage systems.

Model MS-151 contains a normally open (N.O) toggle switch, and becomes activated when the faceplate is manually pulled down. The cover will remain down and in the locked position until it is reset, via an Allen Key. In turn, the station is reset by pushing the faceplate upwards, and turning the reset screw in a counter-clock direction.

Model MS-151 meets the requirements specified in UL S1013, as well as meets approvals from FM, CSFM, New York City Fire Department {287-91-E XII)[66]}, and City of Chicago.

The Model MS-151 is also included in US Coast Guard (USCG) approval for use in marine and other harsh environments, when used with the Siemens 252-point and 504-point USCG approved addressable system.