Fits 41 mm fork legs Innovative design makes tool easier and safer to use than old fashioned pin aligned drivers Anodized aluminum locking ring features knurled finish for secure no-slip grip and positively locks body halves together during use No more worrying about part of the tool falling off and damaging the fork leg or hitting your feet Perfectly weighted to drive seals Body halves are machined from durable carbon steel and feature high quality protective black e-coat with laser engraved markings Patented design .