
Amazon.com: uxcell Inductive Proximity Switch Sensor NPN Normally Open, 6-36V DC, 12 mm Diameter, 4 mm : Industrial & Scientific,

Amazon.com: ATO 2Pcs M12 Proximity Switch NPN NO Inductive Proximity Sensor Approach Sensor,lj12a3-4-z/bx,for 3D Printer Probe Bed Leveling,Replace Small Switches and Limit Switches : Industrial & Scientific,

Amazon.com: Heschen M12 Inductive Proximity Sensor Switch Non-Shield Type LJ12A3-4-Z/BX Detector 4mm 10-30VDC 200mA NPN Normally Open(NO) 3 Wire : ,

DC12-24V(6-36V) Proximity Switch,2-Wire Normally Open Inductive Proximity Switch Sensor,8mm NPN NO Proximity Switch Sensor,

Inductive Proximity Sensor LJ12 DC 6-36V or AC 90-250V Cylindrical Proximity Switch 2/4mm NPN PNP NO NC NO+NC Metal Sensors,