Four blade high efficiency impeller AAA: Advanced technology, Assurable quality, Authentic reputation (impeller, stirrer, rabbler, beater, propeller, mixing ... and oxygen dissolving of biology ferment. Dimensions of Four-Blade PropellersDJdd2hB1B2h1d1d0δ(kg) WeightKSXZSX200254040804010M6-32.4041.842220304540884410M6-33.7762 ... is the same as the inner hole. Four blade high efficiency impeller