Neewer External Flash Battery Pack CP-E4 Replacement for Canon 600EX,580EX,580EX II,550EX,540EZ,MR-14EX & MT-24EX, Neewer TT520,TT560,NW680, NW565,NW985 Speedlite As a professional power supply device, Neewer P-8 battery pack is designed to charge Speedlite with external power input ports, including on-camera flashes from Canon. With 8 AA batteries, it shortens the recycling time and gives more battery flashes between battery changes for flashes. With the CPU circuit design, this device integrates software protection and hardware protection, ensuring higher safety and reliability. Compact, portable, and easy to connect with speedlite Secure and reliable with low-power and overheat indication Faster recycling time and more flashes between a battery changes