[Inner diameter] 2.8/3.3/4.3/5.3/6.3/8.3/10.3/12.3[Material] Alumina 96[Processing] Both-side Polishing[Color] White[Heat Resistant Temperature] 1,300°CThe ceramic washer made from inorganic alumina 96 is a product jointly developed by Hirosugi-Keiki and Otsuka Ceramics, made of a new material that combines insulation resistance, heat resistance, abrasion resistance and high strength.