4-gallon ProSeries Diaphragm Pump Backpack Sprayer. Features Translucent tank, 4in wide mouth opening for filling and cleaning, diaphragm pump to provide compatibility with common fertilizers, weed killers and pesticides in both liquid and wettable powder form, 3-stage filtration system with in-tank removable/cleanable filter, cushion grip poly shut-off with 3 nozzles, and padded shoulder straps.