Well built and adjustable - SLR Sentry 7 .750 Adjustable Gas Block w/ .450 in. Set Screw Spacing

Adjustable gas blocks are one of those things you don't "need" but they can definitely help take your shooting game to the next level during a competition. If you have a slightly gassed up rifle. This can help tune it in. If you have a shorter barrel and running suppressed you may also benefit from this. It can help reduce wear and tear on your internals and give you a slightly better shooting experience, but honestly how many of us outside of a trigger puller are going to use our rifles enough to justify this gas block vs wear and tear on internals? Only you can answer that.

Again you don't need this thing to shoot, or even shoot well. After you use it and setup your rifle it can help fine tune it if that is your thing.