As part of the Amazon Vine program, I was able to test this dual charger including 2x 2600mAh batteries for free.
In general, I also always look critically at these tests and thus represent my current and fair opinion here.

The set is delivered very well and securely packaged in a suitable product box.
The batteries are packed separately and securely. A USB-A to USB-C charging cable
and a quick guide are also included.

I would like to get rid of the fact that many products always have USB-A to USB-C cables - unfortunately these do not work for fast charging, even if the charger used provides the necessary power. Here you have to switch to USB-C to USB-C, which can be annoying if you also have to buy it separately.

The charger itself is very easy to set up and use. You can charge 2 batteries at the same time here. The charge level is shown on a display with bars - one charge level per slot.
Thanks to the USB-C port and a suitable cable, you can even charge them remotely via a large power bank, or connect them in the car.
If a USB-C to C cable is used, the batteries can also be charged quickly via it, which significantly shortens the charging time.

All in all, a very robust set with a good price for two batteries with a charger.