This was my second purchase of a Dakine Cosmo backpack. I got it for carrying essentials on the back of my wheelchair. It is just the right size to carry some emergency supplies like a spare inner tube, some small tools, tire changing levers, and some medical supplies. I've had the first one for 7 or 8 years, and other than fading from exposure to sunlight, it is just like new. The zippers get used almost daily, and have never jammed, even though most of the time I reach behind my back to zip and unzip them. The only reason I got a new one is to go on my new wheelchair!