Enhanced bolt catch will not fit into milled pocket on upper reciver - Yankee Hill Machine Billet Mod2 Stripped Upper Receiver For AR15s YHM-110-B2

Wish the finish was as nice as the Seekins lower. It's an ambi lower bolt catch release, so having a standard bolt catch size isn't terrible. Other than that the upper receiver is beautiful,this thing is beefy in all the right areas. Planned on a cerakote finish from the beginning would definitely recommend.