One of the most advanced chronograph watches made by Citizen, the Eco-Drive Calibre 2100 men's titanium watch also offers stylish lines that nicely complement both business and casual couture. The chronograph timing function includes 60-minute, 12-hour, and independent second-hand subdials, as well as a center sweep 1/5-second hand. It also has a reset button that instantly returns all the chronograph registers to zero. The watch case and bracelet band links are made of titanium--which is nearly 50 percent lighter than steel, but 30 percent stronger. It's also particularly resistant to salt water corrosion, as well as hypo-allergenic--perfect for those with metal allergies. This large, round watch has a thin, flattened bezel with an exterior tachymeter reading in gray. The patterned dark gray dial face is accented by black subdials, and it offers white luminous Dauphine hands (with seconds hand) and a date function at 4 o'clock. The bracelet band is joined by a push-button clasp. Other features include a screw-back case, screw-down crown, scratch resistant mineral crystal with anti-reflective coating, and water resistance to 200 meters (660 feet). This watch is powered by Citizen's unique Eco-Drive, which absorbs sunlight and any artificial light through the crystal and dial to recharge the watch continuously. With regular exposure to light, the Eco-Drive continuously recharges itself for a lifetime of use. This watch's Eco-Drive provides a 240-day power reserve, and it can be recharged with just 3.5 hours of exposure to light.