Professional watch gaskets silicon o ring by size case back sealing washers

Silicone case-back gasket sized from 15mm to 45mm for sealing watch case backs.

⭐ At a glance

📏 Available in sizes from 15mm to 45mm, measured across the inside edge of the gasket

✅ Outside diameter runs 1mm larger than the stated size

Thickness: 0.5mm

Material: Silicone

✅ Fits

Suitable for any watch case back that needs a round sealing gasket matching the stated inside diameter — simply pick the size that matches your existing gasket or case back groove.

Pairing with silicone grease on the gasket helps it seal properly and extends its working life.

⚠️ Please check the inside diameter of your case back or old gasket carefully before ordering, as case-back gaskets need to match closely to seal correctly.