The input and output voltage of the portable charger is DC 5V, which can charge mobile devices anywhere in the world.
As for charging the power bank, it depends on whether the input voltage of the AC charger is compatible with the country you are going to.
• Japan: AC 100V
• USA, Canada, Mexico: AC 120V
• Brazil, China, Hong Kong: AC 220V
• India, Australia, Singapore, Malaysia, Philippines and most of Europe: AC 230V
However, almost all AC chargers these days are 100V-240V, so they can be used anywhere in the world without any problems.