Profoto 901034 Air USB (Black) Complete flash control of your camera, in your hand or from your computer, including flash power and modeling light control. Control an unlimited number of generators and heads on eight channels Profoto Air devices deliver sync signals with a very short delay, just 100s in fast mode. Signal connections are made with either a hot shoe or a cable. These small, handheld devices weigh only 70 g (2.5 oz) including batteries. They pack a lot of functionality and reliability into an easy-to-use control panel. Operating at 2.4 GHz, they are approved for world wide use. Profoto Air systems with sync can also operate with external receivers on older generators or other brands. This USB 2.0 transceiver connects your flash generators to the Profoto Studio Air, software for both PC and Mac that gives you full control of your studio flash system remotely from your keyboard.