High hardness sapphire glass. Watch glass thickness : about 1.2mm.
2mm Double Dome Sapphire Lens Watch Crystal 20 to 40mm Watch Glass Repair Parts
1.0-3.0mm Thick Sapphire Plane Watch Glass Watch Crystal 7-45mm High Quality
Replacement Diameter 20mm-40mm Round Flat Sapphire Watch Glass Watch Crystal
30.5MM*2.5MM Watch Modification Sapphire Glass Watch Repair Replacement Parts
Round Sapphire Flat Watch Crystal 1.0mm Thickness Diameter 17.0 – 31.0
36-40mm Sapphire Glass Watch Case NH35 NH36 NH34 Waterproof UK