The 3008 "Shorty" roller plunger contact is specially designed for use in security applications where size is a limiting factor. The 3/4" housing makes the 3008 the perfect recessed contact for door jambs with restricted space. Unlike ball rollers, our roller plunger wheel is designed to operate with a smaller surface area in contact with the door's jambs. This reduces the likelihood that dirt and other debris will clog the mechanism. The tapered wheel allows for more flexibility during installations.