The Halcyon drysuit inflation kit can be used with 6cft and 14cft cylinders. The 6ft cylinder can be attached directly to the diver's Halcyon backplate and the 14cft cylinder can be secured to a diver's single or twin cylinders.
When doing long dives and/or are using helium-based mixes, use a separate (argon) cylinder to inflate your drysuit to stay warm!