T9 stationary parts are standards for our types:DY51,DY512,DY513 and DY520,complying with DIN24960 and ISO3069 and the mating rings are made of sintered silicon carbide/ssic,reaction bonded silicon carbide/sic,ceramic 99.5%,ceramic 99% and ceramic 95%,tungsten carbide and so on. you can find the detailed dimensions here.