SunFounder DC 9V/650mA Power Supply Plug Adapter Compatible with Arduino Uno R3 Mega 2560/1280 (6 Feet);

Introduction
This 9V/650mA power adapter works with most devices that use a 9V and less than 650mA of power.

Note:
1.Since it provides a max current of 650mA, it cannot drive devices with higher rated current.
2.It's a center-positive barrel connector, of which you should be well informed before purchase.
3.It fits pedals with power ports of positive-tip and negative-barrel, suggesting not recommended for ports of a negative tip and positive barrel.