3 pcs Brown Wired Door Contacts Surface Mount NC Security Alarm Door Window Sensors.These ¾” Door Contact Position switches (DCS) Work with All Access Control and Burglar Alarm Systems

Installed 5 of these so far to replace old sensors from an older alarm system. They seem to work great with no issues. Even work well with a couple of doors that have a gap between the door and the frame.

Did not work. I think something is wrong with my alarm on my truck