Attach to your Schlumpf crankarms to make shifting easier by extending the button along the entire length of the crankarm. Lightwieght aluminum. Works on Schlumpf 170mm crankarms with flat profile only. The EZ-shift levers do not work with other Schlumpf crankarms with the curved profile (172.5, 165, 160 & 152mm). Also, the EZ-Shift levers do not work with aftermarket crankarms. Pair.