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 close to some target 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 Sensor Wire Type: DC 3 Wire Type (Brown, Black, Blue) Switch Appearance Type: Cylinder Type, Metal Shell Output Type: PNP, NO; Detecting Distance: 4mm/0.2''; Supply Voltage: DC 6-36V Current Output: 300 mA Detect Object: Iron Column Sensor Dia.: 12mm/0.5'' Cable Length: 1.1M/43.3'' External Material: Plastic, Metal Net Weight: 47g; Color: Silver Tone, Blue, Black; Package Content: 1 x Inductive Proximity Switch Note: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.