After the endstop holds delivered with the printer broke and I printed some of thingiverse which broke also after time, I decided to design my own STABLE ones.
They fit perfectly for 8mm rods and i have no stability issues. Also they hold REALLY tight :).
the Holes for are for M3-Screws. (4 screws may a bit overwhelmed :D I only use 2 to hold it on playce but for the paranoid ones out there you can screw it up with 4 screws)
Please write, if you want any Adjustments. It may take a week for me to reply.
Just put both sides together and screw them