The RX-15 is an entry-level Receiver from RoboSHOOT. It is designed for the current generation of Fujifilm X-Series cameras and will trigger current X-Series flashes (with the exception of the EF-X8) when used with a separately purchased RoboSHOOT transmitter. Flash syncs up to 1/180 sec are possible with flash units ganged in 1 to 4 groups. Other features include Flash Exposure Lock (FEL), which is useful when recomposing, and Flash Group Settings, which allows you to preview and compare the lighting setup in each group.