Park tool fixed gear lockring wrench hcw17the hcw 17 features two different radius hooks for a precise fit on most fixed gear lockrings the hcw 17 has two different ends featuressized to fit rings with an outside diameter of 41 42 43 and 44mmalso fits single speed cassette hubs using lockrings with external notches11 58 29cm in length for excellent leveragebuy park tool workshop tools from chain reaction cycles the worlds largest online bike store