SP Systems International SPS1 4-Gallon 70 PSI Professional Series Multi-Purpose Backpack Sprayer Stainless steel pump handle, lever, base, and hardware Repairable diaphragm pump module New and improved deluxe adjustable shoulder straps and pads Wide mouth lid with carrying handle Hybrid Viton o-rings and seals made of specially formulated Viton that withstands wide range of chemical attack