U.S. Solid Watch Waterproof Tester- Water Resistant Tester Tool for Watches, Test Up to 2 Watches at a Time for Resistance Up to 6 ATM, Commercial and Home Use, a Product USAGE: This state of the art device will allow you to test the water resistance of your watches up to 6 atmospheres EASY TO OPERATE: The simple, yet highly effective design make this tool easy to use in your home or at your business MULTIPLE WATCHES: This machine will allow you to test up to two watches at a time; More efficiently test the water resistance of your watches with the U.S. Solid Waterproof Tester for Watches BUBBLE EFFECT: If you see bubbles coming from the watch when it is submerged, you have a bad seal; If you dont see any bubbles, your watch is sealed correctly SATISFACTION GUARANTEED: All U.S. Solid products come with a one year guarantee; If you have any issues at all with your waterproof watch tester, simply reach out to customer service, and we will gladly fix the problem, or replace the product