This is a 20,000 mAh power bank. It is of very high quality and is a first-copy version. We also have the original version available for 2,400 BDT. We have tested this first-copy power bank by connecting it to our own mobile phones, and it can easily charge three mobile phones from 0% to 100% on a single charge, meaning it provides around 15,000 mAh of output. This is completely normal as the remaining 5,000 mAh is consumed by the power bank's internal functions. It is indistinguishable from the original in both performance and appearance, but you are welcome to purchase the original version if you prefer. Note: There is no discount on this product, but we offer free home delivery across Bangladesh.