I took the 2-pack K&F CONCEPT compatible DMW-BLK22 (2520 mAh) because I wanted a simple solution: always have batteries ready without going crazy with proprietary chargers or strange sockets. And on this, the strong point is very clear: USB-C charging. Plug in a cable (power bank, phone charger, car, PC) and off you go. For those who travel or take long photo/video days, it's an enormous convenience.

Performance and autonomy
The autonomy is good and, in real use, it behaves consistently: I have not noticed sudden drops or 'strange' behavior. Obviously, compared to the originals (it depends a lot on the camera body and how you record: 4K, stabilization, always-on screen, etc.), there may be a difference, but like spare batteries they do exactly their job: they allow you to continue shooting when the original leaves you on foot.

USB-C charging changes everything
The real advantage is management:
- no mandatory charging base - recharges everywhere

- perfect for backpacks and trips
If you do events, trips, excursions or work where you can't stop, it's a very sensible solution.

Build quality and reliability
The batteries are solid, well finished and do not give the idea of a “cheap” product. Insertion and removal in the chamber ok, without strange games or joints. The fact that they are in double packaging is then the classic smart purchase: you use one, the other is ready or charging.

Things to know (without beating around the bush)
- Don't expect 'miracles': they are great as alternatives/backups, but if you are super picky about the duration identical to the original in every scenario, the original remains the original.
The convenience of USB-C is so great that, for many, it more than makes up for any small difference.

Verdict
If you need a reliable, comfortable spare kit designed for those who move a lot, K&F CONCEPT DMW-BLK22 2-pack USB-C is a good buy. Ideal for travel and long days: less stress, more shots.