This transparent sapphire watch glass has a hardness that ranks nine out of ten in the Mohs scale, making it the hardest material second to diamond. It is also designed to be anti-impact, anti-scratch, and with high electrical resistance, and with very wide optical transmission band from UV to Mid IR. 

• A premium-quality sapphire glass
• An anti-impact and anti-scratch design.
• With high electrical resistance.
• Features a high optical production rate.
• With good thermal stability.
• Features a high melting temperature of 2030 °C.
• With a high hardness of 9 Mohs (second to diamond)
• Purity: 99.99%.
• Density: 3.98-4.1g/cm2.
• Compressive strength: 21000kg/cm2.
• Flexural strength: 4000kg/cm2.
• Infrared transmittance: 85%.
• Dielectric constant: 7.5 - 10.5.
• Place of origin: China.
• Color: transparent or custom-made.