NEEWER AD-360 360W External Portable Flash Light Speedlite with PB960 Lithium Battery Pack for Canon 580EX II, 580EX, 550EX, Nikon SB-900 SB-800 SB-80DX SB-28DX SB-28 SB-27, Sony HVL-F58AM HVL-F43AM, Metz Flash High Power - up to 360w/s, GN 85 (m ISO 1, with AS-S2 standard reflector) Bare bulb - providing even and sufficient illumination. Precise Output - adjusting from full power to 1/128 in 1/3 stop increments Good Portability - compact size and light weight body & accessories. Stable Color Temp - 562k over the entire power range. Advanced Function - incl. Multi flash, Focus-assist beam on/off & High-speed sync triggering. Wireless Commander - controlling flash functions and triggering. Large Electricity - drawing from external power pack (PB96: 11.1V/45mAh). Wide-Range Accessories - incl. softbox, reflector, fold-up umbrella, and beauty dish, etc) Over-Temperature Protection: To avoid overheating and deterioration the flash head, do not fire more than 75 continuous flashes in fast succession at 1/1 full power. After 75 continuous flashes, allow a rest time of at least 1 minutes. If you fire more than 75 continuous flashes and then fire more flashes in short intervals, the inner over-temperature protection function may be activated and make the recycling time about 1-15 seconds.