The HO2 First Stage is Certified for up to 100% Oxygen Service because to the Bulletproof Design of the Hollis HP5 Non-Balanced Flow-By Piston First Stage and Highly Specialized Component Materials and Manufacturing Processes. Specially designed materials, halocarbon based lubricants, and color-coding for easy identification are used to clean and assemble the parts in a clean room environment.
On the market, the Flow-By Piston Design is the only real Fail-Safe First Stage Design. If the High-Pressure Seat fails unexpectedly, the Piston will immediately shift downstream from the High-Pressure Air flowing from the Scuba Cylinder. This feature ensures that the gas flow to the Second-Stage Regulator remains steady. The Regulator First Stage weighs 8.3 oz (235.3 g).