SunFounder DC 9V/650mA Power Plug Adapter for Arduino UNO, R3 Mega 2560/1280 (3 Feet) High quality wall wart AC to DC power supply, with input voltage of 120-240V AC and output of 9V 650mA. Cable length: 100cm (3 feet). With a Center-positive 5.5 x 2.1mm barrel connector, fits positive-tip and negative-barrel ports. Suitable for supplying the Arduino boards (UNO, MEGA 2560, Duemilanove), or some other devices. The Power Supply meets UL safety standards and is made to last longer. Input: AC100V-240V 50/60HZ Output: 9V DC==650mA Cable Length: 100cm (3 feet) Barrel connector: 5.5 x 2.1mm Since it provides a max current of 650mA, it cannot drive devices with higher rated current. Its a center-positive barrel connector, of which you should be well informed before purchase. It fits pedals with power ports of positive-tip and negative-barrel, suggesting not recommended for ports of a negative tip and positive barrel.