Tissot PRC 100 Collection Ladies PRC 100 Sport Chic T-Classic Watch With A Grey Stainless Steel Strap, Black Mother-Of-Pearl Dial & Date Window. The Tissot PR 100 is a classic watch destined to be worn often and for every occasion. It features the simple and elegant face the collection is loved for, with the pared-back aesthetic symbolising luxury, quality and classic style. Mother Of Pearl Mother of pearl is formed in the depths of the sea and harbours very unique features such as iridescence and opalescence. No two specimens are alike, which gives the watch a unique character, especially for ladies watches, both on the dial and on other elements. 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.