Park Tool SBC-1 Spoke ruler Cotter and Ball Bearing Gauge. This handy shop aid is ideal for sizing spokes ball bearings and crank cotters.Has both metric and fractional spoke length markings
For Spokes: Hang the head of the spoke in the oblong hole and read its length on the scale
For Crank Cotters and Ball Bearings: Works just like a gauge for drill bits
Anodized aluminum with embossed markings to allow easy reading and long life