This is a z-probe that attaches to the default platform of 3DR. It's made for an Omron D2F type of switch.There is a slot for the cable to go through. And the probe should be assembled with three M3 screws (10mm long is ideal) through the top of the platform and threaded on the probe.I used this probe temporarily to try to fix a dimensional problem with the build of the printer, the columns were not simmetrical and I built a genetic algorithm in a python script to continuously probe the bed and extract a good set of machine parameters. Once the parameters were tuned, I removed the probe.