Adjustable SB Tactical SBA3 pistol arm brace

Compatible with standard AR-15 magazines

Nylon tipped tensioning set screw

Threaded bolt catch roll pin (included)

Machined from 7075-T6 forged aluminum

Anodized black

Rear takedown pin detent hole is threaded for a 4-40 set screw

Get a rock solid start to your next pistol build with the Aero Precision M4E1 complete pistol lower! This factory-finished lower is ready to roll with a Magpul MOE SL pistol grip and adjustable SB Tactical SBA3 pistol arm brace. With high quality components and fantastic quality of life features, this complete AR-15 lower is a fantastic shortcut to your next finished rifle!A threaded takedown pin detent recess allows easy installation of the takedown pin detent and spring with the use of a 4-40 set screw. Increased magwell flare aids in quick and efficient magazine changes. Marked and milled to accept short-throw safety selectors, but will work with standard selectors as well. To really elevate this complete lower, it's been equipped with the SBA3 adjustable arm brace from SB Tactical, allowing for length of pull adjustments for an optimal fit with almost any shooter.Aero Precision is known for superior engineering and machining. They push the boundaries of manufacturing and challenge the status quo by constantly looking for new ways to develop and evolve.