BNT 207 (OTTO) Boron nitride disc, inner dia × outer dia × thick 55 mm x 99.5 mm x 2.5 mm - used in the following applications, Plasma arc insulators,High temperature furnace fixtures and supports, Vacuum melting crucibles, CVD crucibles, Electronic parts- heat sinks, substrates, coil forms, prototypes, Low friction seals & more.