This is clamps for 25mm conduit (but I believe that you can clamp it over US also). Printed from ABS (for higher flexibility) with 30% infill.
You can screw endstops on this clam and move them on right position on selected conduit (I have them on X/Y for min/max and Z max)
Very usable for relative coordinates and machines with flexible sizes of working area - you don't need to be afraid that your machine will run into hard stop because you will limit it by endstops and not by size.
Don't forget to activate endstops in Marlin configuration!!