Anker Innovations Co., Ltd, commonly known as Anker, is a Chinese electronics manufacturer based in Changsha, Hunan, China. The company's product range includes phone chargers, power banks, earbuds, headphones, speakers, data hubs, 3D printers, charging cables, torches, and screen protectors, among other products.
I agree with the 2 Nitecore 10k's. They are the lightest and lighter than the Nitecore 20k. Back when I bought my 10k I did some research and found the Nitecore 10k had the best energy/weight rating and also had the most useable energy. (Just because a power bank is rated 10k doesn't mean you'll get anywhere close to 10k.) Nitecore comes the closest to the rated capacity. I've had mine for a few years and it is going strong. I bought the Nitecore 20k (because I wanted 30k) and like it, too, but it is noticeably more dense than the 10k.
I have a Dark Energy Poseidon Pro 10200 and really like it. I get about four charges on my phone before it’s out of power. It weighs just over 9 ounces.