[Select reference] The inner diameter of the waterproof ring is selected to be equal to the diameter of the glass The height of the waterproof ring should be less than the height (thickness) of the glass. The outer diameter of the waterproof ring can be selected to be between 0-0.2mm larger than the inner diameter of the watch case groove (It is usually recommended to choose a waterproof ring with an outer diameter larger than the case groove by about 0.1-0.2mm for better waterproofing)

For example, the diameter of the watch glass is 29.5mm, and the inner diameter of the watch case is 30.2mm Waterproof ring optional: 29.5mm inner diameter, 0.35mm thickness, outer diameter is 30.2mm (usable, just right, may be a bit loose) 29.5mm inner diameter, 0.4mm thickness, and 30.3mm outer diameter (recommended) 29.5mm inner diameter, 0.45mm thickness, 30.4mm outer diameter (recommended)