Widened cylinder: diameter 70mm. Can put two large watches at the same time.Suitable for watch inspection,watch maintenance and watch manufacture. Popular with watchmakers and hobbyists.The apparatus is for testing the water resistance of watch cases. 1- 6Bars waterprooftest Atmospheric pressure with stable cast base and excellent quality. Everyone needs one of these, even shops with much more expensive testers still needs one of these testers to locate the leak.