... quality control system/ 3.OEM accepted/ mini water circulation pump MATERIAL OF PUMP CasingCast IronImpellerStainless steelCasing ringhardened S.S,shaftcarbon steelbearing ... equipment in any possible places Features1The motor and the pump united as one, working under water, more reliable. ... install, operate and maintain, less space demand, no pump house needed4Simple structure, less cost, Submersible