I've used a portable jump starter on my car before, and while I was somewhat concerned it might explode in my face or light my car on fire in the process, I am happy to report all it did was work properly. My car was up and running in a few minutes. And given that it was parked in a spot inaccessible by the length of jumper cables my friend Cornelius had, I was even more appreciative of the compact powerhouse's presence and versatility.
My car jump starter is not from Kinkoo, but it does have the same 10000mAh capacity and looks similar in design. Glove box-sized bank with short + and - clamps, ports so the jumper can double as a USB device charger, and a flashlight on the end for use in the dark. Kinkoo's model also comes with car DC and AC chargers / charging capacities, which mine did not. The power bank has enough braun for 500+ uses.
Kinkoo's jump starter is on special for 24% off for a limited time from Dude Exclusives.