Ulac Trek Pro Top Tube Bag 1.2LNot too big, not to small, just optimal is how I would describe the Trekking Pro top tube bag. The Trekking Pro provides an adequate 1. 2 liter capacity, which is good enough for a day trip. Moreover, we understand the importance of space management, and have included two additional pockets on both sides. This way the cyclist can have better access for items such as energy gel, Allen key or snack bar. In addition, on the left pocket we added an extra