By adding weight poucches (sold separately), tank adapting accessories, back plate padding to JT31-D series back pack, a complete BCD emerges. They all have hydro-dynamic air cells, which allow for excellent streamlining. By minimising drag, swimming effort is reduced and buoyancy control becomes much easier than with a conventional jacket style BCD. The minimalistic harness also give more chest room for easier access to attachments and better maneuverability underwater.

The JT31-D- These are complete BCD's with 30Ibf (14kgf) lift double-layered air cell for single-tank use with harness and back pack plate being the difference between the two. Comes complete with the single tank adaptor and its twin tank straps the maximum size of scuba cylinder can be used is 15L (95cft) in capacity.