USB Device Charger: The Compact AC to USB adaptor has (1) USB port with 5V / 1A output at 50-60Hz (Input: AC 100-240V ac 0.15A.) The prongs retract when not in use. It is ETL Certified and provides over current, short circuit and overheating protection. Sized conveniently at 1-1/4" x 1-1/4" x 1-1/4".