Spru of APC Standard E series inserts. Fits any prop with .375" adapter ring recess. 6 each of of 5 different adapter rings.
1/8" (3.2mm) .160" (4mm) 3/16" (easily drilled out to very close 5mm use #8 or 13/64" drill) .231" (easily drilled out to 6mm with letter "B" drill bit) 5/16"
Note, factory drilled hole in APC props should be carefully drilled slightly OVERSIZE. A centering ring should be used to center the prop. The centering ring recess is "on center".