This kit allows you to fill each bag and test the travel before you permanently affix in place.  Why assemble your entire system only to find out you wanted ride height to be 2” lower, or higher.  Just Screw the Schrader Valve into the mounted bag, apply air pressure with the included gauge/filler.  Or, if you are on a budget, you can install 4 Schrader Valves and fill your bags with an external Compressor.

Now that you have a complete FBSS (front/back/side/side) system, it would not be complete if you did not Tee off of your system and mount a Quick Disconnect so you can fill tires or run air tools.  Note:  You must have a 100% Dutycycle Compressor to do this, preferably two, with a 5 gallon tank.