Metal shell, DC type, 4mm detecting distance, 3 wire system.Power supply inverted connecting protection, short circuit protection, non-contact detecting device.When proximity switch is to some object, it will send out control signal.Used widely in the machine tool industry, frequency counters and other automatic control system.Product Name: Inductive Proximity Switch;Model: LJ12A3-4-Z/BY;: Inductive Type SensorWire Type: DC 3 Wire Type (Brown, Black, Blue)Switch Appearance Type: Cylinder Type, Metal ShellOutput Type: , NO;Detecting Distance: 4mm/0.2'';Supply Voltage: DC 6-36VCurrent Output: 300 mADetect Object: IronColumn Sensor Dia.: 12mm/0.5''Cable Length: 1.1M/43.3''External Material: Plastic, MetalNet Weight: 47g;Color: Silver Tone, Blue, Black;Package Content: 1 x Inductive Proximity SwitchNote:Light and different displays may cause the color of the item in the picture a little different from the real thing.The measurement allowed error is +/-1-3 cm.