Dual Action Pull Station 500-893081. The Siemens MSI-20B dual action pull stations are constructed of a durable molded polycarbonate material which is matte finished in red with raised white lettering. The housing accommodates a pulldown lever which, when operated, locks in position indicating the manual fire alarm box has been activated. The pull down lever remains down and locked until the manual fire alarm box is reset. The manual fire alarm box is reset only by opening the hinged housing cover with an allen key and then closing and locking the cover.