The delivers dependable high-flow action that lasts. Piston action mechanism allows high water flow and long-term prime lock. The hand pump is unaffected by water deposits that reduce the ability of other types of hand pumps to hold their prime. Heavy-duty construction with chrome-finished base and spout will resist corrosion and withstand marine environments. Pump requires 1-7/8" diameter hole for mounting. Unaffected by water deposits Heavy-duty, chrome-finished construction | Rocket Hand Pump