I am not a man who always gets a branded products, but for battery equipped units I would never buy something that isn't tested or reviewed. Mophie was my choice for a long time and it is a great product. Cases with 4200 mAh for that price. I don't believe that those batteries hold that cappacity. Not at that size dor sure. When I connect it with a smartphone I will make sure it is a product with the same quality. The Mophie is a great choice, don't complain about the price. And I recently discovered the San Francisco company I-blades that makes a great quality cases for Samsung. I ordered the I-blades smart case for my s6. At the same price with the Mophie I am getting extra battery, additional 64 GB and an air quality sensor. And the best thing is that I can detach the modules when I don't need them. What I'll have is gonna be a Military Certified Case and modules at any time.