Fits conventional nipples. Threading the spoke nipples is the most time-consuming part of wheel building. With a quick-release bit and a cordless screwdriver, you can save a lot of time and ensure that all the nipples are threaded to the same depth. The protruding portion in the center of the bit helps keep it centered and prevents it from slipping out of the nipple. Alternatively, if the nipple is screwed deep onto a spoke, this protruding portion helps tighten the nipples to the same depth on the other spokes.