Park Tool CBW Open End Brake Wrench The CBW open end wrench is great for use on brake bolts, derailleur bolts, or anywhere on your bike that requires an open-end style wrench. The low profile 3. 2mm thick wrench makes getting to those hard to reach areas easier, while the nickel plated steel construction ensures durability. The CBW-1 comes with 8 and 10mm sizes, and the CBW-4 will cover 9 and 11mm size bolts. Features Nickel plated steel construction Low profile to reach tight places Limited Lifetime Warranty Manufacturers Part No: CBW-1, CBW-4 UPC: 763477001115, 763477001177 | Park Tool | Cbw Open End Brake Wrench Cbw-1, 8. 0Mm-10. 0Mm