The Gas Block Genie is a must-have tool for easily assembling your AR platform rifle. Gas Block Genie allows you to install your gas block to the perfect depth and angle on the first shot! It's reusable and comes with instructions. All you'll need is a very fine point marker or scribe. Standard size Gas Block Genie. Fits all .750" barrels. Features: Works with all styles of gad blocks, including clamp-on Easy installation ensures a perfectly aligned gas block #html-body [data-pb-style="62DF8289522E1"]{justify-content: flex-start; display: flex; flex-direction: column; background-position: left top; background-size: cover; background-repeat: no-repeat; background-attachment: scroll; border-style: none; border-width: 1px; border-radius: 0px; margin: 0px 0px 10px; padding: 10px;}#html-body [data-pb-style="62DF8289522EE"]{border-style: none; border-width: 1px; border-radius: 0px; margin: 0px; padding: 0px;}