This backpack is beautifully and intelligently designed, with a back pocket large enough for a light that also double as a charger for cell phones. It's much safer especially when riding home from the gym or the store on these evenings when the sun sets early. The backpack is made of a sturdy but lightweight canvas material but there's a pooket on the exterior made of the same material as the megapuff itself, just turn it on the setting you want...I like the flashing settings...and voila, instant better visibility for the cars passing me buy. The sides of the backpack are also made of the solar light material so it's got this contemporary look....The straps are adjustible and also there are handles like any handbag too. Overall, I love it...and use it whenever I'm in a dark place and am on the go. Highly recommend.