Cast aluminum head and enclosed piston assembly Jam-proof handle return mechanism Includes both h/d 18 flexible hose with coupler and rigid 4 tube Filler nipple / bleeder valve combination Variable stroke design delivers high pressure & high volume Extra heavy follower spring ensures positive priming & uninterrupted pumping action Exclusive flip over follower eliminates grease bypass Three-way loading: cartridge, suction or bulk Develops up to 7500 PSI (517 Bar)