Handy, dandy, and durable, the Park Tool Fixed-Gear Lockring Tool-HCW-17 features two different radius hooks for a precise fit on most fixed-gear lockrings for maximum versatility. Its sized to fit rings with an outside diameter of 41, 42, 43, and 44mm, and also fits single speed cassette hubs using lockrings with external notches. At just about a foot in length, this tool also deliver exceptional leverage for when you're handling more stubborn lockrings.