USB port, plug and play, very convenient. Requires 5V 2A power bank, mobile power, or charging plug (not included) for power supply, greatly extending camera usage time. Suitable for 550D, 600D, 650D, 700D DSLR cameras. Uses multi-protection technology, such as short-circuit protection, over-voltage protection, and over-current protection, ensuring absolute safety during use. The cable length is up to 1.5 m. Long enough, very convenient to put your own power bank or mobile power in your pocket or bag, or elsewhere. Model: -E8 Compatible camera models: For 550D, 600D, 650D, 700D DSLR cameras Input: USB 5V 2A Output: 7.4V Power supply: Power bank, mobile power, and charging plug (not included) Protection: Short-circuit protection, over-voltage protection, and over-current protection Color: black Material: ABS Size: Line length: 1.5 m Package contents: 1 * -E8 Dummy Battery 1 * USB data cable Note: Please use a 5V 2A (output) power bank/mobile power for power supply, otherwise the product may not work normally. Only the above package content, other products are not included. Note: Light shooting 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.