MODUS 600RT MK II SPEEDLIGHT FOR SONY Powered by an Extreme Li-Ion Battery Fast recycle time of 1.5 sec (4x faster than AA power) Up to 600 shots at full power Up to 1000 shots at 1/2 power Built-in 2.4GHz wireless receiver & transmitterUnique wireless connectivity High performance 60GN at ISO 100 200mm TTL Manual & Multi Modes Firmware update via integrated USB Quick-lock hot shoe Ultra-compact MD1 MK II USB powered charger Kit includes MODUS 600RT MKII case & stand1 x HLX-MD1 Extreme BatteryUSB powered MD1 MK II Ultra-compact ChargerUSB cable