Right in between our small and large backpacks you will find this medium size. It has an extra pocket on the front, waterproof lining with a handdrawn pattern and adjustable shoulder straps with a cheststrap. On the inside you'll find an elastic band that serves as a bottle holder and a pocket all over the back that closes with velcro. There is also a name tag to put your info. — body - 27 x 13 x 38 cm— shoulder handles - maximum length 67 cm— elastic band inside - 2,5 x 11 cm materials— body - recycled PET bottles— front pocket - 50% cotton 50% polyester — handle - cotton— zipper - matt white YKK— lining - waterproof nylon— buckles - matt white metal Oops, a stain in your Sticky item! We would advise you to treat it with just a slightly damp cloth. That will do the trick! We wouldn’t advise you to clean it in the washing machine or to use any severe cleaning agents.