This bag should serve as a replacement for my old "Lowepro Mini Trekker Classic", which is something very long in the tooth and can not absorb any additional equipment more. The Flipside 400 is slightly larger than the Mini Trekker of the external dimensions, unfortunately it does not offer more storage space than this. Firstly, the reason is that the padding of the Flipside is thicker. That may be for some an advantage for "normal users" who does not throw his camera backpack through the area, bringing not overly much. Secondly, the subjects do not open far enough to get easily serve up all the equipment. The big selling point - and that's why I ordered the backpack - is of good hip belt, the wearing very relieved one at about six kilograms of equipment. The official dimensions of 25x45x56 cm IATA (sometimes even just 20x40x55 cm) holds the Flipside a well. At the processing can not be faulted - Lowepro builds no cheap scrap. Conclusion: a good processed backpack that shines through high wearing comfort but the space exploits not quite ideal.