I'll start by saying the instructions for connecting these flashes to the transmitter are useless to a novice amateur photographer. The information must be lost in translation, making these lights extremely difficult and frustrating to program for the first time. I almost sent them back just because of this error. Once programmed they are great to use. They do what they advertise and misfires are minimal and in my experience related to a low battery. Have spare batteries ready. Better yet, buy good quality batteries. These outbursts can be chewed up quickly. Be prepared to reset your power settings if you turn off your flashes between uses. I turn mine off when placing an object or changing props. Turning them back on will reset them to 1/128 by default.