EMR-A is a long in development ambidextrous magazine release for .223  AR receivers.  Original concept and design was complete in 2015.  After numerous changes to the mag catch geometry and lever shapes,  final design was made into working prototypes in 2017, and first shown in public at Cola Warrior West III.EMR-A is an ergonomic ambidextrous magazine release.  The placement of its lever is well thought out to closely mirror the magazine release button on the right side.  The portion immediately below the bolt catch’s lower paddle has a lower profile to avoid interference, heretofore a common drawback of popular ambidextrous mag catches, it is also left smooth.  The serrated length of the lever is split into a shallow V shaped serrations (80%) that conform to the curvature of the user’s finger, and straight serrations (20%) that form a natural index point, and provide additional traction.  We refer to the design as Multi-faceted Control Surface, the difference MCS makes has to be felt to be fully appreciated.