The AR-rifle platform is, by virtue of its tubular receiver extension and buffer assembly, not generally compatible with folding stocks—much to the chagrin of those who prefer a compact AR for storage or transport. The Dead Foot Arms Modified Cycle System circumvents that shortcoming with a folding block assembly that allows for a right-side-folding buttstock. Retrofitting the kit, which includes a re-engineered bolt carrier group, buffer spring, recoil spring, plunger, buffer tube with guide rod and end cap, allows a typical 16"-barreled AR to fold to 26.5", and, when extended, does not inhibit the operation of full-automatic or suppressed firearms. The MCS accepts standard carbine or rifle buttstocks along with the company’s five-position, minimalist, all-metal T-Rex stock. Price: $399 (kit), $155 (T-Rex stock). Contact: Dead Foot Arms, LLC; (608) 764-3176; deadfootarms.com.