This powerbank is a useful product. It could load a Samsung Tablet (S10 Ultra) in about 2-3 hours and had still round about 17% left of the initial charge of the powerbank. That's a good result, but maybe not really better than other power banks on the market. But as soon as prices come in, Anker keeps remaining fair to their customers. There's an acceptable ratio between price and quality I think. Moreover, the design is pleasant. Its size is not totally small but "quite small", if you like. It even fits easily in the pockets of your jeans. But I tested it more than with the huge Samsung s10 ultra: It recharges and fuels m Macbook air 15' quite reliably, and its possible to recharge it from about 10% to about 100%. However, the powerbank will be comletely empty thereafter. But don't forget: that's maybe only possible if the Macbook (or tablet, laptop or whatsoever) is switched off or remains at least on standby. That is, because while working on your gadget your powerbank - ANY powerbank in that price range, by the way - can only deliver the energy for the current operations that you are carrying out, but the bank cannot deliver for additional charging of the battery while you are working. So if you really wish to recharge your gadget's battery, always switch your device off or open standby mode! More than that, the capacity of a powerbank that is displayed on the multiple manufacturers' adverts, is the capacity of the host battery, that means it is the capacity of the battery of the powerbank itself. Its final output to your gadget however is LESS than that. My tablet has a 11,500 mAh battery, this power bank here has 20,000 mAh round about. As after charging the tablet I have maybe 17% left in the the powerbank, I guess that it can deliver around 14,000-15,000 mAh in total. But that is said to be normal. A lot of youtube videos taught me so, at least. So: check the total of mAh of your gadget's battery. Then calculate: subtract Anker's total output of maybe 14,000 mAh the total of mAh needed by your device, and if there will finally be some (or almost no) energy left to remain in the power bank, then you are good to go with that model. However if your device needs more energy than the round about 14,000 mAh which this powerbank can deliver, you are better off with a powerbank model with a larger capacity. It will maybe cost a little more, but then you will be safe to fully charge your device. Which ever way you decide, I can recommend my new energetic companion made by Anker. I like it a lot and it charges all my mobile devices the way I want it to do. A good investment, and I will be happy to stay with the brand. My normal Anker chargers with a wall plug (65 Watts for Macbook etc) are also excellent and very fast. So when at home, I am perfectly equipped and all gadgets are fast to charge. And when in the outside or at work, this new powerbank is my best friend ever. I own that Samsung S10 ultra and also an iPadPro 12,9 inch M2, as well as the Macbook Air M2 15,3 inch. Their charging time varies between 2 and 3 hours. Refilling the Macbook should start before it drops to 10% or less, because otherwise the powerbank will not recharge it to 100% but maybe only to 95 % or so. Anyway, a very good result for recharging such a big laptop even. The iPadPro 12,9inch is fully charged in about 2hrs 15 min even ;-) So you can by this powerbank without regret, take care, and enjoy ;-) Photos, from left to right: 17% left after charging the S10 ultra, result: 100% (full!), then: 100% charge on iPadPro12,9, with 32% left in powerbak after charging the iPad. Then: almost fully charged Macbook Air 15,3 inch, after that the powerbank was empty, however, because the Macbook has a powerful batttery with a large capacity.