The Korg KA310 and several other power supplies use this cable. It is not polarized (not squared on either side of the end that plugs into the unit) and looks like a figure 8 when viewed straight on.

This is the Korg OEM part that we purchased directly from Korg. It is not a knock-off. It is fairly lightweight.

Please note that when you purchase a KA310 power supply from Audio-Depot we already include a non-OEM replacement cable for free even though the manufacturer does not include the cable with the power supply.