Ensuring you are Ready for the Road Ahead , the OTR Double Check Valve offers superior support for your air brake system, successfully controlling the air flow into a common line from one of two sources, whichever is currently working at the higher pressure. Ensuring your exhaust mode is never hindered by the backflow of air, the shuttle of your double check valve ensures successful operation of your ABS system. This OTR double check valve meets and exceeds OEM expectations, efficiently transferring air quickly to optimize your air brake system. In the end, this heavy duty double check valve offers prime brake function with safety in mind. FleetPride is your First Click in Heavy Duty .