They are two useful one . You can do the backpack and shoulder bag. We used the high quality material PU , they are two different colors. Of course we offer any colors you need. The round of opeing is nicer than the flat one. And it is bigger enough for the use. You can put the Ipad, books when you travelling or studying. It is good for girls and boys. Also the size of backpack strap is adjustable for all the clients. Lining is polyester and we keep the inside zipper pocket for your important things too. Thanks .