The AirSource 3/4” Manual Heater Shut-Off Valve keeps you Ready for the Road Ahead™ with the ability to open and shut off the valve during cold winter months. This heater shut-off valve can be universally connected to a 3/4” heater hose, effectively terminating coolant flow from going to your heater core. This action is needed when the heater is not being used during hot months or you’ve discovered an emergency leak in the HVAC system. Ensure your cabin is properly heated, no matter how harsh the environment may be outside your truck. FleetPride is your First Click in Heavy Duty®.