USB port, plug and play, very convenient.Need 5V 2A power bank, mobile power or charging plug (not included) for power supply, largely prolong the time of your camera.Suitable for 550D, 600D, 650D, 700D DSLR cameras.Adopts multi-protection technology, such as short circuit protection, over-voltage protection and over-current protection, which ensures the absolute safety during use.Cable length is up to 1.5m. Long enough, very convenient to put your own power bank or mobile power in your pocket or bag, or at somewhere else.Model: -E8Compatible Camera Models: For 550D, 600D, 650D, 700D DSLR camerasInput: USB 5V 2AOutput: 7.4VPower Supply: Power bank, mobile power and charging plug (not included)Protection: Short circuit protection, over-voltage protection and over-current protectionColour: blackMaterial: ABSSize: Line length: 1.5mPackage Contents:1 * -E8 Dummy Battery1 * USB data CableNote:Please use 5V 2A(output) power bank/ mobile power for power supply, if not, the item can not work normally.Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.