Hand-operated knapsack sprayer, suitable for non-aggressive liquids. It can be used in the garden for spraying pesticides, fungicides and chemicals for the treatment of plants. The tank is made of recyclable polyethylene resistant to UV rays, equipped with a transparent band to control the liquid. Its peculiarity is the stainless steel piston. Equipped with an upper carrying handle, it can be transformed for use with right or left lever. The operating lever is transferable from both sides. It is supplied in the standard model with a PVC lance, but is also available in aluminum, telescopic, brass, as well as with different combinations of nozzles.