Dual Displacement Pump combines piston and diaphragm technology. Wide mouth 6-Inch opening allows for easy filling and cleaning/servicing of pump; Cap has a built in carry handle and wand clip. Large 6-Inch basket to catch (First stage filter) contaminants and debris when filling tank. Self cleaning JetClean design keeps 3-D removable filter from clogging from built up residue and debris. 4-Gallon Poly Backpack Sprayer.