An adjustable gas block is a firearm component that allows the user to adjust the amount of gas flowing into the gas system. This can be important for tuning the firearm to function reliably with different types of ammunition or to reduce recoil. Adjustable gas blocks are typically installed on AR-15 rifles, but they can also be used on other firearms.
There are many different types of adjustable gas blocks on the market, each with its own advantages and disadvantages. Some of the most popular types include: