The Hollis 150LX HO2 is the perfect option for Divers requiring a regulator using higher percentage Nitrox mixes up to 100% Oxygen. The 150LX 2nd stage is fully Balanced and uses a durable Brass valve housing. The Regulator is super smooth to breathe and has an easy to use Pre Dive switch to avoid any unnecessary free flow and loss of gas. The HO2 DIN 1st stage is a workhorse, super reliable and easy to maintain.