Metro Machine Selector Valve, 1/2in. Port, 20 GPM Flow High strength cast iron construction Open crossover type valve with a chrome plated, pressure balanced spool When the spool is moved and one pair of outlet ports start closing, the other pair of outlet ports will open Small, reliable and easy to install 5.88in.L x 2.44in.W (including knob) x 3.62in.D