With the Bulletproof Design of the Hollis HP5 Non-Balanced Flow-By Piston First Stage the HO2 First Stage is Certified for up to 100% Oxygen Service thanks to Highly Specialized Component Materials and Manufacturing Processes. Cleaned and Assembled in a Clean Room Environment with Specially Designed Materials, Halocarbon Based Lubricants and Color-Coded for Easy Identification.

The Flow-By Piston Design is the only true Fail-Safe First Stage Design on the market. The Piston will automatically move Downstream from the High-Pressure Air coming from the Scuba Cylinder if there is an unexpected malfunction of the High-Pressure Seat. This feature guarantees a constant Gas-Flow to the Second-Stage Regulator. The Regulator First Stage weighs 8.3 oz (235.3 g).

Out of stock

SKU: HO240.3558 Categories: ,


  • Bulletproof Hollis HP5 First Stage Design
  • Non-Balanced Flow-By Piston
  • Fail-Safe First Stage Design
  • 300 BAR/4500 PSI DIN Connection
  • DIN Hand-Wheel Connector: Oxygen Green for Easy Identification for Oxygen-Use-Only
  • Material: Durable and Corrosion Resistant Marine-Grade Chrome Plated Brass
  • 4 LP 3/8″ Threaded Ports
  • 1 HP 7/16″ Threaded Port