The powerbank comes in a nice but simple brown cardbox. It comes with everything you need: the powerbank itself, a short manual, 1 usb-c to usb-c and 1 micro usb cable. The bank itself comes in a soft bag to prevent scratches and the glossy part comes with a protection film attached, to absolutely ensure that nothing gets scratched before you get the chance to do it.
With my old powerbanks I only could assume the percentage of the leftover capacity. I also really like the fact, that you can use the usb-c port for both, charging the powerbank and charging a device, since it's a pain with a usb-c smartphone and a micro usb powerbank.
Also you can, but probably shouldn't, charge the powerbank while charging 2 devices at the same time. That's pretty handy if you're traveling and don't want to carry multiple chargers with you or you only have one wall socket.
All you need is 1 charger and 3 cables. Connect the powerbank via a micro usb cable with the charger and e.g. a smartphone with a usb-c to usb-c cable and your smartwatch with the third usb cable to your powerbank. Naturally the charging is rather slow this way, but for a overnight charging or on a long bus/train travel it's a really useful feature.