This is a tank bag that secures with four magnets. It can also be used as a waist bag with a carrying handle and a detachable belt. The zipper allows for adjusting the thickness to increase capacity. A smartphone sized 160 x 73 x 12mm can fit in the mesh pocket. Although it's a product from over 20 years ago, it has only been used about 10 times for long touring trips. There is some discoloration on the clear case inside, please understand this before purchasing.