The Combat Folding Stock KIT Fits any gun that already has a JCS RVA or gun mount in the upper position only (not attached to the grip).Combat Folding Stock kit for JCS RVA's and gun mounts only. Already own a JCS RVA? This kit fits JCS gun mounts or RVA's which are attached to your marker in the upper position (will not work with grip-mounted stocks). This product will not work alone. You get the stock, slide, hinge, and mounting hardware. Just use a 5/32 Allen wrench for installation.