The Shield Arms SA-15 Stripped Folding Lower Receiver represents a revolutionary advancement in AR-15 design. Unlike traditional folding AR-15s that require bulky, heavy folding adapters installed between the upper and lower receivers, the SA-15 features a patented folding mechanism integrated directly into the lower receiver. This innovative design eliminates the need for separate folding adapters, resulting in a lighter, stronger, more compact folding rifle or pistol. The SA-15 is a complete mil-spec lower receiver that accepts all standard AR-15 parts, while providing true folding capability for compact storage and transport.