Necessity being the mother of invention....I needed a 27mm crows foot for my lite AR build... the Chinese made aluminum AR barrel nut I ordered from China (before the virus scare) has a facet that would not allow the Amazon bought crows foot to fit. Machinest at work spent about 15 minutes programming our 250k waterjet he uses for aircraft parts to make this one in the pics 7075 T3 .90 aluminum....I’m better than good now.