Transparent compartment for smartphones with the ability to manage it. The design of the bag involves a convenient placement of accessories on the bike. It is attached to the frame with Velcro. It looks very compact, but the review claims that it is very spacious. And indeed it is. You can put a spare battery in a bag, another little thing, and there will be a lot of space. The bag is sewn perfectly, the fabric has a waterproof impregnation.