Constructed of stainless steel and 6061 T-6 billet aluminum, unlike the stock pumps, which are made from weaker cast aluminum, plastic and brassThis performance pump is a direct replacement for the inefficient OEM aluminum 6-vane stator sectionPump spacer to use stator with OEM Yamaha reduction nozzle is available separately (PART #4809-0220)Requires the use of a large hub Magnum impeller PART #4809-0196 (12/18 pitch) or PART #4809-0197 (13/19 pitch); sold separatelyUses OEM Yamaha bearings and sealsIncludes 12-vane stainless pump, pump cone and dual cowling with brass fittings