The Zipper Cosinus bag is a tailor-made proposition for those who want to use the loading potential of the main triangle of their bicycle frame down to the last square centimeter. This is a bag that is made-to-measure especially for you. This bikepacking tailor-made bag has an extremely practical two-chamber design, which allows for better organization of equipment and easier access to the contents. The presence of a partition means that the bag does not tend to take a round shape - so there is no problem with rubbing the legs against the scattered sides of the bag. The partition between the chambers is attached with Velcro and if you want, you can remove it in case you need to transport a larger size in it. You can also detach it only at the end and in this way transport the tent frame inside without giving up the advantages of the two-chamber solution. We place the partition approximately 2/3 of its height. 1/3 of the height is for the upper chamber, and 2/3 for the lower one. The edges in contact with the frame along their entire length are equipped with a system of loops which enable fastening the bag with Velcro in the most convenient places. The set includes eight fixing straps lined with non-slip material that stabilizes the bag and protects the frame. Three of the straps are longer so that they can be used with the main pipe, which usually has a larger gage. If they turn out too long for your frame, shorten the hemless side using scissors. Zipper Cosinus bag is made of Cordura TPU - a material with extraordinary abrasion resistance. A thick inner layer of thermoplastic polyurethane provides the fabric with complete and lasting waterproofness. Zipper Cosinus bag is closed with a splash-proof zipper, the location of which you decide yourself. Reflective logos on both sides of the bag to effectively increase visibility. The pictures show different options of reflective prints. Currently, in Cosinus bag, we are applying a graphic with the motif of the mountains.