pneumatic switch (air interlock valve, valves) 

Air Interlock Valve is vapor recovery fittings installed on bottom of the loading adaptors to lock the brake by the driver outside of the truck.

Features & Advantages:

1. Main shaft sealed prevents contaminants from entering the sealing area.

2. Compact design fits for all pneumatic valve locations.

3. Universal mounting plate is fit for all API adaptors and vapor fittings.

4. Rigid mounting prolongs valve life.