Steatite Ceramic usually called C221 High frequency ceramic, which is a low cost material with high electrical resistance at high temperatures, good mechanical strength and a very low dielectric loss factor. Such properties make it ideal for high frequency, low loss, and high voltage insulation. Steatite has been used for many years in large-scale industrial systems, household electronic appliances, aerospace and automotive applications, and specialized electro-technical instruments such as cathode-ray tubes.