You are looking at a Brand New 4 Channel Radio Slave strobe flash transmitter & receiver. It is ideal for outdoor and in studio work. You will not have to worry about the messy cable anymore around you. The radio slave transmitter can be operated via the camera hotshoe or through the sync cord. It will allow you work simultaneously in studio or on location. The best workable range is about 50 feet. The receiver uses two AAA batteries.