The Adafruit 1352 4-Way 2.1mm DC Barrel Jack Splitter
Quadruple your power adapters with this wonderfully simple 4-way power jack splitter. All you have to do is connect a standard 5.5mm/2.1mm sized plug into one end, and behold, four identical plugs to use! We like the rugged molding on these adapters, and they're really handy when you have a project with multiple pluggable devices.