Western Digital has released a 6TB hard drive, billed as the highest capacity in a 3.5″ model. The secret behind the added storage is helium.

The UltraStar He⁶ is produced by HGST, a Western Digital subsidiary. The space in which the disk platters spin is filled with helium rather than air. Because helium is seven times less dense than air, there’s less drag.

That means the drive requires around 23 percent less power to run and is quieter, cooler and lighter. There’s also less turbulence inside the drive, meaning its possible to get seven disk platters in the space rather than four or five, which brings the extra capacity.

Though the concept is simple enough, the challenge in manufacturing was dealing with the problem that helium is more prone to leaking. HGST says it developed a completely hermetic seal to deal with that issue. One fringe benefit is that the drive is also watertight and could be used in liquid-based cooling systems.

HGST also notes that the helium doesn’t pose any risks and the drive contains less helium than a balloon.

For now the drive will be aimed at business rather than consumers. Organizations including HP, Netflix, Huawei and CERN have all been in talks with HGST about using helium drives in settings such as data centers.