Low profile gas block for barrels with a outside diameter 0.750" at gas port.
Included: Low profile gas block; screws, gas roll pin & hex keys = comes ready to install.
This is the gas block you'd use when upgrading from a 2pc drop-in handguard to a 1pc free float. The 2pc setup will have a fixed front sight post w/ gas block or a railed gas block (e.g. DPMS stlye) - when changing to 1pc, it gets removed.
Once a low profile gas block is installed, you can install a free float handguard that extends past the gas port with the low profile gas block 'inside'.