Great brand, great product - Aero Precision M5E1 .308 Enhanced Upper Receiver

Thoughtful engineering on this piece is that the bolt catch pin uses a small screw, super easy. Especially because the extended paddle I bought didn't fit so putting it off and on a few times then going with the standard paddle was no issue. Which was cool. Also changed the ejector port cover which was again engineered for ease. The small thoughtful things really stand out in this product. Using their upper and handguard is a must with a few exceptions. The upper, lower and handguard together make for a supremely smooth, tight fitting (if you want) product. I had a few misses with the tools that I thought would surely scratch but didn't.