Really the magic that FoldAR designed was an upper that folds — the stock folding is done by way of a Dead Foot Arms MCS adapter (more on this later). The real innovation from FoldAR lies in their folding upper, while the stock folding is achieved using a Dead Foot Arms MCS adapter ...
SIG MCX LVAW ‘Black Mamba’ 300 Blackout (300BLK) Piston AR SBR/PDW Features Demo: Subsonic/Supersonic Ammo Adjustment, Slimline Folding Stock, Tactical Handguard/Rail Removal (Video!)byDavid Crane