Every Wolf Tooth steel insert is machined and nickel plated in-house at Wolf Tooth's Minnesota HQ “ designed to be lightweight, lean and pair perfectly with the Wolf Tooth Pack Wrench “ sold separately “ these inserts are ideal if you're likely to be travelling with your bike or want a trail-ready mobile wrench kit. This insert fits Race Face Cinch aluminum spindle bolts, frame pivots, and other 16mm hex applications.