You'll need to use a power supply if you're powering more devices than the USB power connection can support by itself. This power supply comes with the green Make Controller Kit screw terminals already attached, so it's ready to plug straight onto your board and can provide up to 1.7 amps.

The prongs on the power supply are US-style, but the power supply can accept 100-220V AC, so all you need to add is a plug adapter for international use.