Z axis endstop spacer

This works on the Folgertech 2020 prusa, I'm not sure about other Prusa variants.
No matter what endstop I used, the endstop would slowly slide down print after print unitl the nozzle would crash into my build plate. So I made a spacer to keep it from sliding down. Quick and simple.

I'm using the Stronger Z endstop (http://www.thingiverse.com/thing:1177943) from http://www.thingiverse.com/pjvpjv .

Along with the Adjustable Z endstop (http://www.thingiverse.com/thing:1261300) from htt