This component is a MUST HAVE if you are installing a PRS stock or you have a back plate that is thicker than the standard, or if you are stacking.
The A2 spacer works with all A2 and Rifle Length Buffer Tubes.
Simply thread in the A2 spacer form the back of the lower receiver, before you install the buffer tube. Depress the Buffer Retainer Pin, and screw in the A2 Spacer, so that is holds down the Buffer Retainer Pin. Now you may add your A2/Rifle Length buffer tube with Quick Pins or whatever End Plate you would like. Simply tighten down the buffer tube to its ridge stop and you are finished. To remove, reverse these steps.