This pull station, although similar in appearance (with the exception of the labeling) to my Pyrotronics MS-501, it is actually a very unique device. It is a dual-stage pull station. Pushing in the “Push Here” part initiates the first stages, and that part actually stays pressed in, instead of popping back out like you would expect. Pulling down the lever triggers the second stage, as you would expect. Click on the link below for a more in-depth explanation of this pull.