The Elinchrom BRX 500 Monolight is packed with professional and convenience features you'd expect from a company of Elinchrom's caliber. Forget about tripping over PC cords. Although this head accepts one, it also has a built-in EL-Skyport Receiver with eight frequency channels that can handle four distinct groups of flashes. The optional transmitter not only allows you to trigger your flash at distances up to 393' but gives you control of power, on/off, modeling light functions and Speed Sync activation. Free software for Mac and PC computers is available with the transmitter, adding additional features such as Flash-Delay for strobing effects. Add an optional USB Wi-Fi module for computer control. You can even use specially designed apps that allow full remote control via your for iPhone, iPad or iPod Touch. This item is sold as seen for spares or repair. Please read the description in full before purchasing. Spares and repairs items do not come with a warranty but do represent potentially excellent value. All faults or issues are fully described. Please Note: This unit powers on but does not include a flash tube or modeling light. Sold as is.