The RE-A5 Receiver Extension is a seven position receiver extension designed to work with the VLTOR A5 system. This receiver extension is slightly longer than the traditional M4 receiver extension and is designed to work with Mil-Spec dimensioned M4/AR-15 type collapsible stocks. It is made from impact extruded 7075-T6 aluminum with hard coat anodized finish. The positions are numbered and are visible through the witness hole on most stocks. It helps with snag-free sliding of the buttstock.