The DT-1.2 precisely machines frame & fork disk brake tabs removing paint & material to ensure they are flat & correctly aligned with the pads & rotor Misaligned brake mounts are one of the key causes of brakes rubbing squealing or generally underperforming the facing of disc mounts is therefore a key part of proper frame or fork preparation Works on forks with 100 mm open dropouts & forks with closed dropouts using 15 mm & 20 mm thru-axles Works on frames with 135 mm open dropouts & frames with closed dropouts using 12 mm thru axles in 135 mm 142 mm & 150 mm lengths