Specification Binding : Electronics Brand : Panopticon Tech Label : AuthorizID Manufacturer : AuthorizID PackageDimensions_Weight : 0.6 PackageDimensions : L:4.00 X W:0.50 X H:0.50 PartNumber : RDCAU-3 ProductGroup : Photography ProductTypeName : SURVEILANCE_SYSTEMS Publisher : AuthorizID SmallImage_Height : 51 SmallImage_URL : https://m.media-amazon.com/images/I/317lLi71OOS._SL75_.jpg SmallImage_Width : 75 Studio : AuthorizID Title : 3 pcs Recessed Brown Door Contacts NC Security Alarm Door Window Sensors With Magnetic Reed Switch. These ¾†Door Contact Position switches (DCS) Work with All Access Control and Burglar Alarm Systems Weight : 0.6 WeightUnit : pounds