The new AF201FG was designed with the active photographer in mind, including a dust-resistant and drip- proof, all-weather construction that prevents the entry of water and dust into the lens. It provides an advanced flash application, including bounce flash functionality, which is adjustable to angles of -10 to 90 degrees vertically. The AF201Fg flash unit, coupled with its weather-resistant body, provides yet another tool to enhance the photographic experience while keeping in mind the extreme conditions our photographers go to get the perfect shot. The AF201FG flash has an assignable mode button that allows the shooter to program their settings to their liking. Users can select from 5 modes including, Off, P-TTL (leading curtain sync), P-TTL (trailing curtain sync), Manual (full), and Manual (1/4). Powered by two AA batteries.