The Betts Industries Aluminum Pressure / Vacuum Normal Vent is a dual purpose vent designed to provide both pressure and vacuum relief for cargo tanks. This compact, interior mount vent is ideal for use with MC306 and DOT406 cargo tanks. It features a rollover protection design. This vent is designed to provide reliable and efficient pressure and vacuum relief, ensuring the safety of your cargo tank. FleetPride is your First Click in Heavy Duty®.