I put a ball valve on mine so i can shut it off at the cane.
For the one in the prior picture, the brass balve valve is kept on the end of the hose. That way it can be used to shut off water flow to change from a nozzle to a gutter rinsing device, or to simply shut either off.
Instead of turning the fireman's nozzle off and on, my ground tech prefers to use the ball valve that stays with the hose. It works well like this for us.