This is a Z-max endstop that uses the original z-min endstop switch, the part press fits into the extrusion.
I am using this with a Duet Maestro for power loss recovery.
I have also remixed clips to keep the endstop cable tucked into the extrusion slot.
Update 10/23
Added version to secure using a 2020 t-nut and screw. Based off of https://www.thingiverse.com/thing:4630372
The author marked this model as their own original creation. Imported from Thingiverse.