One of the world's most popular sprayers, you can't go wrong with the Solo Classic backpack 475 15L sprayer. This diaphragm knapsack sprayer is your go-to for all applications, but particularly if you use marker dye. The pump handle is also great for both left or right handed users.
 
Other features of this reliable and robust garden sprayer includes:
Desired Viton seals
Wide padded adjustable straps
Wand holder on the pump handle for maximum user-friendliness.
Solo's trigger handle and 50cm wand assembly with flat fan and alternative cone nozzles.
German made
 
Some light assembly is required.