Product Details: Update your semi truck with enhanced control of its PTO, with the Chelsea 12V Power Take-Off Solenoid Valve and Valve Cap Assembly that ensures you're Ready for the Road Ahead™. By rapidly opening or closing, this replacement valve is able to activate / deactivate a vehicle's PTO mechanism. Built with a seamless design to allow for a straightforward installation. FleetPride is your First Click in Heavy Duty®.