Great gas block - Presma Low Profile Gas Block

I've designed quite a few AR's and used several different gas blocks. Some good some not so good. Presma is one I'd recommend. They're easy to install, They fit great, and they're easy to time. A trick to the allen screws to secure the block. Once you have it timed properly and the allens are snug not tight, remove them one at a time and add a small amount of blue 242 Loctite then tighten them to spec.