Input: AC 100V-240V 50/60Hz; Output:3A max @ 5V DC ; Works with device that draws less than 3A, such as 0.5A, 1A, 1.5A, 2A, 2.5A, 2.7A, 3A. Pack of 5. DC connector is 5.5mm x 2.5mm, compatible with 5.5mm x 2.1mm. Comes with a female DC barrel connector. You can easily screw wires on it without soldering. Polarity is internal "+", outside"-".