This kit includes a Di866 Mark II Flash, Calumet Speedlight Powerblock 900, and dedicated cable to connect the Nissin flash to the Powerblock.The Di866 Mark II Professional for Canon is Nissin's flagship model featuring innovative features and professional performance. The flash features a main light with a powerful guide number of 60 as well as a sub flash with a guide number of 12 (ISO100, 105mm) that can be used as a fill light when bouncing the main flash. The Di866 Mark II's user friendly color display with auto-rotate let's you intuitively and easily access all of the flash's functions. In addition, the flash includes a usb port for firmware updates, a PC sync socket, and an external power port.The Speedlight Powerblock 900 is the perfect power source for wedding and location photographers who rely on their speedlights for high volume flashes from a single charge, fast recycling, and consistent flash output. The extremely portable battery pack can conveniently clip onto your belt or be carried with the included shoulder strap. The battery pack features a high-quality Ni-MH battery that will provide up to 500 full-power flashes from a single charge and will recycle most flashes in just 1 second. The Speedlight Powerblock 900 fully charges in 2 hours.