Heschen Vierkante Inductieve Nabijheid Sensor Schakelaar Niet-Schild Type SN04-P3 Detector Afstand 5mm 10-30VDC 200mA PNP NO+NC 4 Draad

The Z axis limit switch on my Shapeoko 3 router wasn’t working. I replaced it this one and it works perfect.

This is a a nice little inductive sensor. It detects metals and magnets really well.It's just the sensor that behaves like a switch. It'll switch a circuit on or off depending on whether it detects a material in front of it. Works to replace limit switches or other proximity switches.If you don't have a circuit to test, you can kind of make use of the LED for detection, but you'll still need a power source. I tested it with a 12V battery and it seems to work ok, but the current drain is quite high.

I’ll probably end up buying more.

Seems fine, behaves as expected. The only caveat is that it has one extra wire that isn't listed on the spec sheet.