Steel, hex, 10mm, tool.
The Traildonkey 3.0 uses a 10mm hex bolt to secure the derailleur hanger. In the event that you need to replace the hanger out on the road or trail (think: Dirty Kanza, etc) you need to have a 10mm hex tool on hand. Few multi tools have a 10mm bolt. The Topeak 18 multi tool does have a 10mm but we are not aware of others. If you don’t own that tool and don’t want to replace a multi tool already in your quiver we’re happy to offer this simple 10mm micro tool that we made just for TD3. The tool is small enough to fit inside any frame bag and interfaces with a standard multi tool hex wrench to create a secure T connection for actuating the 10mm hanger bolt.