The Honeywell 944TSP is a 3/4" contact with a 3/8" magnet and Form A SPST (normally closed contact) wiring.The 944TSPs staggered "T" terminal design simplifies screw-in installation by eliminating splice, solder, and tape -- a staple of Honeywells exclusive "T" terminal contact series. The 944TSP can be used to secure any access point, including doors, windows, and basement/attic entrances. Also known as -Honeywell Sensors 3/ 4 D REC TERM 3/ 4-3/ 8 MAG WHT - 944TSP-WH