The Strato II Multi is a flash trigger and it can be used as a wired or wireless shutter release. The 2.4 GHz. transmitter and receivers offer ranges of more than 150 meters and sync at speeds of 1/250 second.* Transmitters feature an innovative TTL pass-through hot shoe - allowing full TTL mode to be used with a camera mounted flash. Receivers offer flash wake-up functions. * It's fast and powerful - perfect for your studio or location work. *On compatible flashes and cameras