A type of battery-replacement external power supply with multiple outputs that is typically used with guitar effects pedals. This type of power supply is often used to power the stompboxes in a rig containing two or more pedals, since it can power multiple pedals at once, replacing either individual batteries in the pedals or individual wall-wart power supplies for each pedals.
The defining feature of an isolated power supply is that each power output is completely indepedent from the others — each is electronically isolated (thus the clever name). The advantages to this are said to include reduction in noise and more consistent, stable power.