2x Flat Rubber Watch Gasket Ring Case Back Seal 6-39mm Screw Down Replacement

Flat-profile black case back gaskets, 6–39mm size range – rectangular section, not round O-rings.

⭐ At a glance

📏 Size range: 6–39mm

Sizes are shown as inner × outer diameter — pick your thickness from the second menu

✅ Use: flat case back seal for screw-down backs with a groove or recess

Profile: flat, rectangular cross-section, black, matte finish

✔️ Condition: new

• Fits by dimension, not by watch model – match the gasket to the size of your existing case back seal
• Suited to screw-down case backs that have a groove or recess for a flat gasket
• Replaces a flat gasket with a flat gasket – flat gaskets and O-rings are not interchangeable