Wand is fine, seal washer not so much. As others have said not a perfect tight fit. A problem when using strong chemicals. Should not need to tighten with pliers to stop leaks. Tried a O ring in place of washer and did not work so had to deal it as is
Is there an extension for the 61900 to make a long/higher reach for spraying taller trees?
Unfortunately there is not a way to make the wand any longer than what it comes with. There is another product called the Chapin Slide Pump Sprayer model 6002 which offers maximum portability and can be used in any container simply by dropping the weighted strainer into the solution and pumping with the slide pump. The sprayer features an 84in heavy duty nylon reinforced chemical resistant hose and a brass adjustable nozzle for fine mist to coarse stream. The brass pump develops pressure up to 150 psi and allows you to reach targets over 30 feet away. There is a video on the product page which shows hows to use this type of sprayer.