The concave V-Groove button face offers an excellent ergonomic feel and self-centers the index finger as pressure is applied. The horizontal, parallel serrations help slippage in the vertical orientation while minimizing drag in the horizontal direction for finger retraction. The BAD-EMR also features a lightweight skeletonized back to offset the weight gained from the fully solid button face and slightly increased height to equal the weight of the standard mil-spec magazine release (approximately 0.002 lbs). BAD-EMR is compatible with all lower receivers that accept mil-spec magazine release buttons. RSR - NV03002526