Citizen BY1030-50L Radio Controlled Moon Phase, rugged and functional. The Citizen BY1030-50L is a powerful men's watch that perfectly combines technology and style. This model features a robust steel case and strap, and a deep blue dial with an elegant moon phase indicator. Thanks to advanced Eco-Drive technology, this watch runs entirely on sunlight, so you'll never have to replace a battery again. Available at WatchXL. * 42 mm case - modern size that looks rugged and wears comfortably. * Eco-Drive - charges via sunlight and artificial light. * Radio-controlled - always the right time thanks to automatic signal reception. * Perpetual calendar - day and date automatically remain correct. * 10 ATM water resistant - suitable for swimming. Advanced technology for everyday convenience. The Radio-Controlled function ensures that the watch automatically synchronizes with time signals worldwide. This means you're always accurate to the second.