ProAxle axles are tempered, rectified steel and give you the precision needed by all the ProAxle crowns and wheels. The bronze (not brass!) bushings, tailored on the ProAxle standard 3/32" (2.38mm) axle, get rid of the sloppiness found in most off the shelf kits. The M2 set hexagonal screws keep wheels and crowns fastened on the axles, using the Allen wrench. A 'professional' Allen wrench that we advise to use is the FACOM "Micro-Tech hexagonal screwdriver, 0.9x35mm p/n 84E.0,9x35"
