An inductive proximity sensor that can be used for 3D printers and CNC machines, among others.It detects metal objects within a distance of 4mm from the sensorVoltage: DC 6-36V Dimention: M12x10x55mm Detection Distance: 4 mm Output current: 300mA 3 Wire Polarity: NPN Ouput Status: Normally Open Part number: LJ12A3-4-Z/BX Detection objects: Conductor