High Performance Octopus Regulator Pneumatically Balanced Downstream Demand Valve Lightweight, Compact and Comfortable Diver Adjustable Inhalation Resistance Venturi (Free-Flow) Control New Compact Profile Built-In Anti-Freezing Heat Sink Feature Cover: Flexible Thermoplastics Case: Ridged Thermoplastics Heat Sink: Anodized Aluminum Diaphragm: Elastomeric Polymer Zeagle Onyx II Octo