The Serfas ST-131 is a well equipped tool with a micro package. Inside you will find a 1.5, 2, 3, 4, 5, 6, and 8mm allen key, with the 8mm actually built into the tool and not some Silverly cap over the 5mm that you will inevitably lose. Additionally there is a T25, T30, phillips and standard screwdriver, and of course a bottle opener. Thanks to the compact shape, the tool is easy to get into tight spaces and provides adequate leverage. Roadies and racers will love the diminutive size since it can eaSilvery be stashed in a jersey pocket, or small bag.