There are several companies in the industry offering carbon fiber wrapped barrels. What makes BSF different is that their barrels are not carbon fiber wrapped, but they are carbon fiber sleeved or jacketed. Also, the carbon fiber sleeves of BSF barrels are perforated to aid cooling.
The difference is that in the case of wrapped barrels the carbon fiber actually hugs the barrel and touches it all along its length. In the case of BSF barrels, the sleeve of perforated carbon fiber touches the barrel only at four contact points: near the chamber area, before and after the gas block mounting portion and near the muzzle threads. The space between the barrel and sleeve allows air to flow through it and cool the barrel faster and more efficiently.
The carbon sleeve also works as an isolator and resists the heat transfer to the outside surface. As shown in the video below, the owner of the company grabs the barrel of the rifle after doing two mag dumps (60 rounds):
Actual base barrels are made of 416R stainless steel. The following chamberings are available for AR-15 barrels: .223 Wylde, .300 Blackout, 6.5mm Grendel and 6.8mm SPC. There are also BSF barrels chambered in .308 Winchester and 6.5mm Creedmoor for AR-10 pattern rifles.
BSF barrels are manufactured in the USA. They are available through Rainier Arms. Right now the .223 Wylde barrel with 1:8 twist rate is the only one listed on their website with a $569 price tag.
Here is also a video by Rainier Arms telling about these barrels
This company and their products are another proof of how small businesses drive the industry with the innovation they bring to the market and the passion they do it with.