Amazon.com: DIGITEN 4 Digital Blue LED Tachometer RPM Speed Meter + Hall Proximity Switch Magnet Sensor NPN + Sensor Mounting Holder for Lathe Conveyor Belt : Industrial & Scientific
Amazon.com: PSN17-8DNU, Sensor, Inductive Prox, 17mm Square, 8mm Side Detection, DC, NPN, NO, 3 Wire,10-30 VDC : Industrial & Scientific
Amazon.com: Baomain Capacitive Proximity Sensor Switch LJC12A3-5-Z/AX NPN NC DC 10-30V 200mA 1-5mm Blue : Industrial & Scientific
Amazon.com: Taiss 2PCS M12 4mm Sensing DC 5V NPN NO(Normally Open) 3D Printer LJ12A3-4-Z/BX-5V Cylinder inductive Proximity Sensor Switch Work Voltage 5VDC Special for MCU : Industrial & Scientific
Amazon.com: Hall NPN Sensor, NJK - 5002C Hall Effect Sensor Proximity Switch NPN 3-Wires Normally Open with Magnet : Industrial & Scientific
DIGITEN 3 Wire DC 6-36V NPN NO M18 IR Photoelectric Proximity Sensor Switch Sensor with Reflector: Amazon.com: Industrial & Scientific
uxcell 4mm Inductive Proximity Sensor Switch Detector NPN NO DC 5-30V 200mA 3-Wire SN04-N for 3D Printer Probe Bed Leveling,MCU Board: Amazon.com: Industrial & Scientific