The Porter Force series features a military-inspired design with an occasional color difference in fabric. The fabric used in the front pocket and the fabric used in the bag itself is subtly colored different, making it a reproduction of the fabric that is rare to be seen in military goods. The bright orange color on the inside contract to the simple appearance of a military jacket, and the light and softness is a truly first-class item. This product is compatible with B5 size, but the main compartment and front pockets are equipped with plenty of gusset, so it can store more than it appears. Furthermore, the shoulder strap is made to be removable, so you can carry it with you in a clutch style. There is a removable pocket on the inside that can be used as a pouch. Product Overview: Main opening: Double zipper exterior/zipper pocket x 2, Interior/Key hook x 1, Open pocket x 2, Removable pocket x 1 (Can be used as a pouch by itself, width 8.7 x height 5.3 inches (22 x 13.5 cm).