I have a Dramm “touch ‘n flow” water wand, a moderately expensive thing which worked very well, except that like so many similar things, the lever valve failed after a few years of age, but little use I might add.
Above, the wand. Note that the handle is molded rubber over some structure that contains the valve… it is designed to be unserviceable.
Above, one can carefully cut the rubber cap off the valve assembly and unscrew the white nylon cap with a 10mm socket. The old spring is shown, rusted and broken into three parts and it would not return the valve to the off position.
The valve spool looks the colour of brass… but on close examination, this one is plastic. Deception, but it is probably better than brass (which is more likely to corrode) which may be fitted to newer wands.
A spring which rusts and the molded covering designed to prevent service is built in obsolescence.
Above, the restored valve which is now accessible for service.