Thank you for viewing. This is a Dickies shoulder bag, a sacoche. I used it once or twice and then stored it in a dark place, but I am selling it because I no longer need it. The approximate dimensions are as follows (measured by a layman): height approximately 18.5cm, width approximately 25.0cm. It has enough capacity to hold a 500ml plastic bottle and still be able to close the zipper. How about it for everyday use, music festivals, etc.?