AT3 Tactical AR15 Mil-Spec Bolt Catch Blue. AT3s bolt catch is a great addition to your next build or a replacement for a lost or damaged part. This piece will fit on any mil-spec style lower and a good deal of aftermarket receivers for the AR15. Specifications for AT3 Tactical AR15 Mil-Spec Bolt Catch: Manufacturer: AT3 Tactical Gun Model: AR-15 Fabric/Material: Steel Features of AT3 Tactical AR15 Mil-Spec Bolt Catch Mil-Spec dimensions Black Phosphate finish or colored Cerakote finishes Package Contents: AT3 Tactical AR15 Mil-Spec Bolt Catch What firearm models does the manufacturer say AT3 Tactical AR15 Mil-Spec Bolt Catch is compatible with? The manufacturer suggests that AT3 Tactical AR15 Mil-Spec Bolt Catch is compatible with AR-15AT3 Tactical AT3-BC-01-BLU: AR15 Mil-Spec Bolt Catch Blue