The Casio G-Shock G-Steel sports a solar panel that converts even the weakest shine of light into electric power. Inside, a rechargeable battery with great power storage capacity, you'll never have to worry about the battery running down because it's a solar battery. The Casio G-Shock G-Steel’s structure boasts a double-layer foundation of stainless steel and resin and fine resin which is what creates the sleek beauty of metal. The Casio G-Shock G-Steel watch mixes class with rough and tough, style with adventure!