... air curtains 1,Centrifugal type,Natural wind and PTC heating wind dual application,CE GS approved.With plug,easy ... and maintenance. Elegant design without any screws. 3,PTC heating element is with safe non-conductive surface, overheatprotection,high efficiency, ... toughness intensified. 5, High quality motor,whose shell is made from aluminium , is corrosion resistance,of high efficiency, low noise ...