Technical Customized Zro2 Zirconia Ceramic Insulation Washer. Customizable Colors: Available in White, Black, Brown, and Blue. High Precision Tolerance: OD and ID tolerance as tight as 0.001mm. High Density Material: Zirconia density exceeds 6 g/cm3. Superior Hardness: Hardness over 9 on Mohs scale. Excellent Wear Resistance: Superior to aluminum oxide with longer life cycle. Low Thermal Conductivity: Less than 3 W/m.k at ambient temperature. Custom Dimensions: OD 1-50mm, Length 10-800mm available. Multiple Certifications: RoHS, Reach, and ISO9001:2015 certified.