Air-cored reactor has no iron core and only has winding, the magnetic circuit is non-conducing magnet so the magnetic resistance is big, the inductance value is low and is the constant. dry air-cored inductor has the advantages such as low noise, good linearity of reactor value, good ability of resisting short circuit current and heat output and no fastener on the mechanical structure, etc. so it has a perfect overall performance, simple structure and basically no need to maintain and can be used both indoors and outdoors. The new product in recent years, dry magnetic screen, base on the original advantage, can also basically eliminate the magnetic interference and magnetic pollution. When installed, the its electric distance with other electric appliance is considered. series reactor, shunt reactor, starting reactor, filter reactor, smoothing reactor, earthing reactor, test reactor, etc can all be manufactured air-core structure.