Adjusts Rear Bolt Spring Pressure and allows you to mount any "upper position" item #661xx JCS folding stocks. Covert your older Trigger Frame mounted JCS Stock today!

Adjusts using 3/32 hex wrench. The JCS RVA won't wobble! JCS locking ring design locks against the rear of the marker receiver and provides an extremely stable and solid mount for our folding stocks. This is the same part used in our folding stocks. Fits Spyder MR-1, MR-2, Sonix, more* - SPYDER ONLY.