The Topeak FastFuel TriBag is a slim and stylish top tube mounted bag designed for triathletes. It offers quick and easy access to essentials without adding much weight or bulk to your bike. It's the ideal size for carrying energy bars, a smartphone, wallet, tools, or other small items. The bag features a clear TPU top for easy visibility of contents and can be mounted using straps or triathlon top tube water bottle bosses.