Used to monitor the status of a door or to provide an initiate signal to Securitron?'s XDT delayed exit logic timers and DPA door prop logic timers.DPS-W Concealed Door Position Switch for Wood DoorsBoth components require drilling a 3/4" [19mm] diameter hole in the door and frame directly opposite one another. The DPS-W style is a Normally Closed switch (SPST). The distance depends on the door type and gap between the door and frame but is in the 1/2"-3/4" [12-18mm] range. Includes a magnetic switch and a cylindrical permanent magnet.DPS-M Concealed Door Position Switch for Metal DoorsBoth components require drilling a 3/4" [19mm] diameter hole in the door and frame directly opposite one another. The large magnet is needed to overcome the shielding effect of a steel door. The DPS-M style is a Normally Closed switch (SPST). The distance depends on the door type and gap between the door and frame but is in the 1/2"-3/4" [12-18mm] range. Includes a magnetic switch and a cylindrical permanent magnet.Specification DataOperating Temperature: -40 to +150F [-40 to +65C]Switching Current AC/DC (max): 0.4AMagnaCare? lifetime replacement, no fault warranty