Prepare your semi truck to be Ready for the Road Ahead , with the Power Products 6" Counter Balance Rain Cap that provides enhanced protection for exhaust stacks. Due to its sophisticated design that opens and closes when an engine is off, this replacement is able to prevent rainwater and other elements from entering an exhuast system. Crafted with a zinc-plated construction to deliver long-term protection for exhaust accessories. FleetPride is your First Click in Heavy Duty .