The breathing circuit's total volume is about 12.5 litres including the diver's lungs. It is designed to ensure that the breathing resistance is as low as possible. Through a system of built-in non-return valves, the gas can only pass in one direction. The breathing circuit has a full face mask including hoses, canister and bellows.

The dosage of gas is made to the breathing circuit from the gas supply via the regulator block.