Feature:1. Professional watch Oring watch gaskets are used to keep watches waterproof, prevent water getting into watch.2. High quality rubber material, flexible and wearresistant and durable, high elasticity and reliable in use, will not damage your watch3. Including a total of 10 different sizes to fit different crowns, suitable for watch makers and watch repairing workers to use.4. Easy to install, take out the lever, put it into the waterproof ring and install the lever, easy and convenient for installation.5. Professional watch repair accessories, give you a satisfactory experience and has exquisite workmanship.Specification:Item Type: Watch Crown O-RingMaterial: Rubber Color: Black Applicable Crowd: Suitable for watch maintenance professionalsApplication Scenario: Used to keep the watch level waterproof, prevent water getting into watchSize: Approx. 3.2 x 1.7 x 0.75mm / 0.13 x 0.07 x 0.03in3.2 x 1.8 x 0.7mm / 0.13 x 0.07 x 0.03in3.4 x 1.8 x 0.8mm / 0.13 x 0.07 x 0.03in3.6 x 1.7 x 0.8mm / 0.14 x 0.07 x 0.03in3.65 x 2.15 x 0.75mm / 0.14 x 0.08 x 0.03in4.6 x 3.2 x 0.7mm / 0.18 x 0.13 x 0.03in4.25 x 2.25 x 1mm / 0.17 x 0.09 x 0.04in4.2 x 2.8 x 0.7mm / 0.17 x 0.11 x 0.03in4 x 1.8 x 1.1mm / 0.16 x 0.07 x 0.04in3.8 x 2.2 x 0.8mm / 0.15 x 0.09 x 0.03in.Package List:1 x Storage Box 1 x Box of Watch Crown ORing