Inner diameter single bore Aluminous porcelain ceramic tube. Resistance to high temperature. Capable of the temp up to 1600 degree celsius(2912 Fahrenheit) 1000V Insulation high corrosion resistance scratch proof and Good chemical stability. Application. Mainly used in electric heating elements protection sheaths insulators. Shape and Size. Tapered single hole 6mm inner diameter for the hole 25.3mm diameter in the base. 24.5mm overall length. Made of high-grade Al2O3 Alumina Ceramic which ensures great mechanical strength and stable performance while working.