Save yourself some money - Aero Precision AR-15 BAR Barrel Nut and Shims

I have built multiple AR’s and typically love AP but this thing is the most poorly designed product I have ever seen. There is no flat surface with which to use a crows foot wrench and nut uses the highly undesirable “four hole” configuration that makes wrench selection difficult. I can’t be more disappointed in aero. Don’t buy this