The ProMag PM237 is a magazine block adapter which easily installs in a standard Ar-15 lower receiver to allow the use of 9mm Colt SMG pattern magazines. This is the key component that you must have in order to make your AR-15 9mm conversion work. The block is constructed of high strength polymer with steel hardware roller ejector and bolt stop. - ProMag PM237 - Converts from standard AR-15 lower to 9mm AR-15 lower - Allows for use of 9mm Colt SMG magazines - Made from high strength polymer with steel hardware - Matte Black
Determined at checkout.