Atomic Aquatics B2 Sealed DIN Regulator, Blackthe Atomic Aquatics B2 system combines the signature second stage design and materials of the T3 with a Chrome plated Brass first stage. The result is an incredibly high performance regulator system that is approachable for every diver and every budget. Featuring a balanced flow thru piston with Atomic's jet seat high flow stainless steel piston and an exclusive self lubricating high pressure seal system, the B2 ensures low friction and maintenance.