High quality switching 'wall wart' 'wall adapter' AC to DC 9V 1A wall power supply. These are switch mode power supplies which mean the output is regulated to 9V. They take 100-240Vac 50/60Hz input and output 9V 1A. These will power most projects that don't require more than 1A of current. Center-negative 5.5x2.5mm barrel connector.
They are design to take up ONE position on your outlet strip or wall outlet. These will convert international voltage (100V-240Vac 50/60Hz) automatically; no transformer needed. The cable is 4.5 ft. long. Blue LED indicate supply OK. Great for many electronic projects!
There are 3 things to watch for when choosing wall adapter:
1) Voltage and Current (9V, 1A)
2) Plug size (2.5mm)
3) Center polarity (Negative center)