Used in conjunction with the Elinchrom SPEED Transmitter and Transceiver RX (neither included), and free downloadable EL-Skyport software, the Elinchrom EL Skyport USB RX SPEED Transceiver can provide total remote control of Elinchrom RX flash units, including flash power, modeling lamp on/off and flash synchronization and much more via any Mac or Windows computer. The EL-Skyport software also offers additional features, such as the programmable Flash Delay, Flash-Counter, and other control features. This transceiver does not require a battery.