The bolt-on Tank Top works only on bikes equipped with top tube bosses. There are now two bolt setback standards, so choose your options carefully! The 100mm setback is the current standard (Salsa EXP, Trek, Specialized to name a few). Reference the diagram at www.cedaero.com to ensure proper fit. Think of this as a go-to pack for all the items you need to quickly access like cell phone, food, keys, credit card and ID, etc. Depending on your other equipment you may be able to stash a tube and repair tools as well. The Bolt-on Tank Top has two stainless steel bolts that secure a HDPE plastic stiffener as well as Velcro OneWrap cinch on the stem to keep it secure on your bike's top tube without flopping. The zipper opens easily allowing quick access while you are on the go. The foam padding provides some cushion as well as shape to the bag. Inside the bag is our silver lining which brightens up the interior. The interior is equipped with a flat mesh pocket, as well as a key hook. 100% made in USA.