AR-15 Steel Gas Block 0.750" Low Profile - Short Neck- Black
This gas block is intended for use on barrels that lack a gas port journal shoulder. If it is used on a standard AR-15 barrel, there will be a noticeable gap between the gas block and the shoulder. While this gap will not affect the function of the gas block, it may not look aesthetically pleasing.
Please see the photo for reference - Short Neck