An anodized aluminum heat sink on the 2nd stage along with the external diaphragm on the 1st stage improves the cold water performance of the Onyx II regulator.
Second Stage: Downstream valve Balanced Diaphragm Dive/Pre Dive Venturi Control Diver Adjustable Breathing Sensitivity New Compact Profile Anodized aluminum heat sink.
| Second Stage Materials: | |
| Cover: | Flexible Thermoplastic |
| Case: | Thermoplastic |
| Poppet Seat: | Elastomer |
| O-rings: | Buna-N |
| Diaphragm: | Elastomeric Polymer |
| Exhaust Valve: | Elastomer |
| Mouthpiece: | Silicone |