Park Tool CNW-2 Chainring Nut Wrench This handy tool fits securely into the slots on the reverse side of a chainring bolt so it doesnt spin while you loosen the bolt. Designed specifically for the job, the revised CNW-2 (replaces CNW-1) makes removing chainring bolts much easier. Features Double-ended to fit most slotted-type nuts The outer width of both ends of the CNW-2 are nominally 12mm wide One end has a two outer tips nominally 2. 7mm wide each, and the other end has tips of 3. 8mm each The blade thickness is nominally 1. 35mm Manufacturer's Part No: CNW-2 UPC: 763477002068 | Park Tool | Cnw-2 Chainring Nut Wrench Cnw-2