... structure of tubular electric heating element is in a metal tube into the heating wire, and the ... the two educing club connecting with power, it has a simple structure, long life, high thermal efficiency, good ... 10,Φ8.5,Φ8,Φ6.5 Length:200mm5000mmSurface treatment: a variety of plated nickel, passivation, black, spray.Note ... certification : UL TUVquality gurantee TUV / UL certification spiral heating pipe