The Fleece Performance TapShifter allows you to shift your 2001-2005 GM Allison Transmission with the touch of a button just like the 2006 and newer trucks. Perfect for towing, drag racing, daily driving and everything in-between, the TapShifter installs in no time and provides factory-like operation, functionality and styling. The TapShifter can be used in the gas or diesel 2001-2005 trucks with an Allison Transmission.