IP20

Provides protection only against solid objects larger than 12–50 mm. It does not protect against water and is suitable for living rooms, bedrooms, and offices.

The nominal voltage indicates the voltage at which the USB port operates. 

5

The standard operating voltage for most USB devices. Ideal for smartphones, tablets, headphones, powerbanks, and small electronic devices.

2.1

Supports faster charging for smartphones and tablets. Suitable for larger batteries or devices with fast charge.