Very good panel, sufficient for batteries up to 15A. In combination with consumption, it maintains a steady current for charging a 12V/7.5A battery with simultaneous power supply at 3.5 watts consumption. It also has a good adjustable solar charger with a maximum of 10A. It's worth the money.

It is made in China. 5Watt for 17€ for a Chinese product is a bit expensive. I measured it with a Multimeter, in relatively strong sunlight and it consistently outputs 22 volts. It seems to be a powerful panel. The quality of the materials used in its construction is not as good as, for example, a German panel.
2/8/23 edit: From 1000 to 1800 with full sunlight, it did not charge the car battery (60ah). It is not suitable for high ah, as the panel's wattage is very low. For mobile phones and small devices like lamps or for camping, it is fine...
I bought it for charging car batteries, which is why I give it 2 stars. Also, anyone who buys it should know that besides the panel, they need to buy a Programmable Voltage Meter (PVM).