M12 Inductive Proximity Sensor Switch PR12-2DN Cylindrical Type Detector 2mm DC12-24V 3-Wire NPN NO(Normally Open) CE

This is a well-built, heavy-duty inductive proximity sensor. If you don't know what that is, you probably don't need to be ordering one. If you're looking for one, then if the specs meet your requirements, I wouldn't hesitate to get it. The switch works very predictably and is perfect for my application as it triggers at the same point every time. This one is meant for rather close-range sensing, but it works perfectly!

I used this proximity switch for 2 different Arduino projects I built. It works out well on both. I may integrate this one into a tractor project on a permanent basis.The 17mm mounting hole is a common enough size that makes integrating it really simple.I would buy again.