MVB is based in Deerfield Florida and they’ve recently released a collapsible stock, sold as the MVB ARC Stock,  for the AR platform that’s been receiving some very good press. The difference between the MVB ARC and others is that with the ARC you keep the same bolt carrier group; in fact, you can also use the stock with a 9mm bolt carrier group by removing the weight on the 9mm carrier. The ARC uses a buffer (H1, H2 and H3 are available)  and spring capture detent that holds the spring and buffer in the buffer tube allowing for a more traditional take-down of the weapon. MVB is now accepting pre-orders at an M.S.R.P. of $395