proximity sensor & proximity switch 1) inductive or capactive 2) Sensing distance 2-10mm ... M8, M12, M18, M22, M30; 5) Different application, DC 3 wires, DC2 wires or AC 2 wires. TK series ... sensing distance, from 5mm to 35mm; 5) Different application, DC 3 wires or AC 2 wires. TC series column shape ... Different column diameter, including M18, M30; 5) Different application, DC 3 wires or AC 2 wires.