Heschen M8 Inductive Proximity Sensor Switch PR08-2DN Cylindrical Type Detector 2mm DC12-24V 3-Wire NPN NO(Normally Open) CE

8mm thread size and 2mm detection spacing is nice and compact. I'm using this for a 3D printer and it's on the shorter size for a detection gap but it works well. The shorter gap means a bit more accuracy in my opinion.

Good price and works well

good product and great price

I tested this M12 sensor at an operating voltage of 24VDC (should work the same at 12VDC as well). The sensor has a rated sensing distance of 2mm with a steel target, and I found this to be accurate. The included installation hardware seems to be a good quality. Take note that this sensor has an N/O output, so the output is OFF until the sensor sees a target, at which point the sensor output turns ON. This sensor output is NPN, so it SINKS current from the load (it will connect the output wire to "ground") when the output is on. In my testing, the sensor works fine and meets its specifications. I like that the status LED shines into a transparent plastic "ring" on the rear of the prox, making it easy to see the status of the sensor from any angle. Many other sensors just have a single LED on the back which can be difficult to see once the sensor is installed. Overall, the quality is good, although the sensing distance is a bit low compared to other proxes in this form factor. Perhaps that may suit your application better than a sensor with a larger detection range.