Tissot SeaStar 1000 Quartz Collection Gents Seastar 1000 Chronograph T-Sport Watch With A Grey Stainless Steel Band and Black Coloured Dial. The Tissot Seastar 1000 merges style and performance without compromising either. The diving inspiration shapes both the appearance and the functionality of this watch. It maintains its performance to a pressure of 30 bar (300m/1'000ft), combining underwater sports and a preference for a sophisticated Swiss timepiece. The diving theme continues through elements such as a unidirectional bezel, a strap with a divers' buckle and extension, plus luminescent hands and markings. Water Resistance All Tissot watch cases undergo several tests, including a water resistance check. Tissot tests the watch's ability to resist impacts and pressure, as well as the penetration of liquids, gas and dust by replicating the real-life conditions in which the watch may find itself. Sapphire Crystal Glass A sapphire crystal gives a watch the following properties: extremely high resistance to impact and superior screen and hand readability thanks to its transparency. Because it is the strongest material after diamonds, it is used in fine timepieces for its anti-scratch prowess. Sapphire crystals can take many forms and give the watch a variety of looks: flat, domed, concave or ground.