AC wall voltage of the Wireless Speakers

The Audyssey Wireless Speakers are sold with a power supply specific to the region in which they are purchased.  U.S./North American units are equipped with a 110 V power supply, Japanese units are equipped with a 100 V power supply, and units sold in Europe/Asia are equipped with a 220 V power supply.  If you take your speakers out of the country a step-down/step-up transformer is needed.