This magazine well conversion block is used to allow the use of 9mm magazines and ammunition with a standard .223 AR15 lower receiver. The conversion block fits into the magazine well and is held in place with a hex screw that pushes two opposing pins outwards, locking the block securly into the lower receiver. The standard AR15 magazine catch/release components work with this conversion block - including the Bullet Button and B-15 magazine locks.
You may use RRA LAR-9 10 round magazines with this conversion block. It is also compatible with C Products 9mm magazines, and modified UZI magazines.
