The pneumatically balanced ZEO is an engineering marvel of precision, durability and comfort. It uses a durable chrome plated marine brass metal valve to deliver a phenomenal breathing experience with extensive diver control over the air flow profile at any depth. The ZEO comes comes with an in-line hose swivel, inhalation effort control, dynamic adjustment technology dive/pre-dive switch and a super comfortable orthodontic mouth piece. The new cold forged, over-balanced diaphragm FDXi first stage is environmentally sealed. The in-line design limits the pressure loss inherent in L type first stage designs making the FDXi more efficient and lighter due to it's compact form.