The Electro Harmonix 9DC-500 Power Supply grants you an easy tidy setup. Delivering 9 volts DC this power supply will ensure your pedal is given the ultimate fuel it needs to perform at its best. Play without the burden of electrical noise tainting your set use time and again thanks to immense durability and equip yourself with the kind of quality that only Electro Harmonix can provide. Specifications Product Code: UK9DC-500 Input Voltage: 230V Output Voltage: 9V DC Suitable For: Classic Holy Grail