The end cap is designed to be glued or epoxied into the hole at the end of a handle. A hole is provided to allow the use of a lanyard made of cord or strip of leather. The end cap has been designed to fit into 5/16 inch diameter holes although depending on processing it might fit into smaller 1/4 inch diameter holes. Always measure your parts before drilling.
The main body of the cap is lengthened so that it may be inset into a larger one inch diameter hole for a different appearance and some extra adhesion area when glued into place.
A smoother version of this design may be found
here:
https://www.shapeways.com/product/BE6ZLPMWU?key=11844bcab20e844e11b5d0fd4e8c3cf1