Complete ETI technology for a full package of whole equipment design,manufacture and testing; Highly efficient three-dimensional flow unshrouded impeller,professional aerodynamic design and structural design for optimum aerodynamic characteristics, resulting in the impeller of over 92%. Optional means of regulation including inlet guide vane regulation, variable frequency regulation, etc., achieving maximum range of regulation and maximum energy efficiency;Optional impeller materials including titanium alloy, stainless steel, casing can cast or welded by stainless steel, meeting rigorous requirement for strength and corrosive resistance.