Feature:1. Professional Test Machine: This is a professional tester specially designed to test the water resistance of watch cases.2. High Efficiency: The unique design of this watch tester allows to test 2 watches at the same time, which can save time greatly.3. Convenient Observation: The cylinder is designed to be transparent, that you can easily observe the waterproof status of the watch.4. Easy to Operate: Just press down the watch lever, press exhaust button to let the air out, and observe whether there are air bubbles in the watch, no bubbles appear indicating that the watch is well sealed.5. Aluminum Material: The tester is made of premium aluminum material, which ensures excellent performance and long last durability.Specification:Item Type: Watch Waterproof TesterMaterial: AluminumColour: Red, whiteUsage: Watch waterproof tester, used to test the water resistance of the case.Package List:1 xWatch Waterproof TesterNote:Please allow 12cm error due to manual measurement. Thanks for your understanding.