The Hypro 6500 Series, 6 Roller, pump acheieves up to 21.8 GPM and 300 psi.   5/8" Solid Stainless Steel shaft that resists corrosion.   

Herbicide users:   Cast Iron pumps lasted up to 140 Hours before failure.    Ni-Resist pumps lasted up to 332 Hours before failure.   Silver Series XL pumps ran over 1000 hours and still met new pump specs!