Speedflow manufactures a large range of adapters to suit almost all threads. These bulkhead adapters are designed to go through firewalls and bulkheads to join a hose and seal of a compartment at 90°. It can also be used as a mounting point if located by a bracket and secured with a jam nut. They are manufactured from steel and ENS plated. Use 392 series jam nuts to secure. Speedflow - Australian Made. Steel - Fully Reusable. ENS Plating. Use with 200 Series Hose Ends. The Best Quality.