The Fizik Saddle Pack uses the unique Fizik clip system with no straps. A tab on the pack slides into the receptacle under the saddle shell. The ICS clip on the bag has three positions so you can customize the angle of the bag. The bag is made from water resistant material and zipper. It has a reflective safety patch and a tail light holding strap. Must have Fizik ICS compatible saddle to be able to use bag.