Charges in Sunlight or Indoors with no batteries to change, ever. 180 Day Power Reserve Low Charge Indicator and Time Reset Advisory Water Resistant to 100 Meters (suitable for swimming or snorkeling, but not diving) Day & Date Display Second Hand Luminous hands and markers for night-time visibility Solid Titanium Case is 1/3 Lighter than Stainless and Nickel-Free so it's hypoallergenic Flexible and comfortable rubber strap Aprrox. Width of case, 38mm not including setting crown