Fast-up rear system, with flat-mount universal brackets for compressor and tank to be custom mounted to the floor in the trunk.  Valves mounted to tank for easy installation.  Please note this is a universal fitment for tank and compressor, and is considered a custom installation that may require fabrication.

Steel shocks measure 9.5" collapsed, 13.25" extended (measured bolt-center to bolt-center)

Aluminum shocks measure 9.5" collapsed, 13.75" extended (measured bolt-center to bolt-center)

What's the difference between the steel and aluminum shocks?  Steel shocks have a pretty basic design inside and out.  This keeps the price low, and the shocks still ride well and are very reliable.  The aluminum shocks have a more advanced design inside and out - This allows for optimum reliability, as well as the most comfortable ride available and the best performance available.  They have a wider range of comfortable travel, so they're very easy to adjust and most people find that they can ride lower with these shocks.  If you are looking for the best air shocks available for your bike, these aluminum shocks are what you are looking for.