The Battle Arms Enhanced Bolt Catch offers Enhanced Control Surfaces, Better Ergonomics, Lightweight Engineering. The Versatile Modular Design allows for Future Add-On Product/s. FeaturesCompatible with Norgon Ambi-Catch Without InterferenceRaised "T-Shaped" Heel Provides Positive and Distinctive Control Surface for Bolt Lock Back Bold Horizontal and Diagonal Serrations Provide Positive Purchase 8620 Heat Treated Cast Steel Black Phosphate Finish