Access Control, RFID Reader, UHF Reader manufacturer / supplier in China, offering 25-35mm Detection Range Normally Close Open Aluminum Alloywire Door Contact for Metal Doors (SDC-51NO), Normally Close or Open Aluminum Alloy Wired Reed Wire Door Contact for Metal Doors Alarm System (SDC-51NC), ABS Plastic Wire Door Contact Magnetic Switch with Fail-Safe Feature for Access Control Security (SDC-44BNO) and so on.