Conical measuring aid for bicycles, works with a tape measure to find the center of any recess from 6mm to 30mm. Works with 8mm crank bolts, Shimano crank fixing bolts, and hollow spindles.

Put the hook of the tape measure in the recess, with the tape measure going in the direction of the arrow.

Printing instructions

Doesn't require any specific strength so settings and material are pretty much whatever you want. Doesn't need support, the arrow should bridge just fine. Layer height can be whatever you like.