The 16inch barrel will need the carbine gas length system.
Most of the barrels on this page come with the gas block, however items BABL556022F and BABL556014F do not come with a gas block.
The Ballistic Advantage Performance Series 5.56 AR Rifle Barrel 17.7" model does come with a gas block.
The Ballistic Advantage Performance Series 5.56 AR Rifle Barrels 13.7" model is carbine length.
These Ballistic Advantage Performance Series 5.56 AR Rifle Barrels already include a pinned low-profile gas block.
The 17.7" Ballistic Advantage Performance Series 5.56 AR Rifle Barrel uses a mid-length gas system and would require a mid-length gas tube. It will also need a 0.750" gas block.
The Ballistic Advantage Performance Series 5.56 AR Rifle Barrels do come with a pinned low profile gas block.
According to the manufacturer the Ballistic Advantage Performance Series 5.56 AR Rifle Barrel 10.3" model has a carbine length gas system.
The Ballistic Advantage Performance Series 5.56 AR Rifle Barrel model BABL556004F comes with a pinned gas block.
This will be a carbine gas system length.