Allows you to run SRAM Transmission or a SRAM UDH derailleur hanger on your Salsa bike that uses their Alternator 2.0 dropout system. Designed to line up perfectly with the non-drive side Salsa OEM dropout in the second hole (longest wheelbase) position. CNC machined out of 6-series aluminum for durability and black anodized for good looks. A longer, 1.0 pitch axle is required to complete installation (axle not included). We've used the following axles with good success:301STD - 3x.75x.244” STD slitter with 60° DB .005”R