Kusuguru Better Keks Zipper Backpack(vertical) (horizontal bottom) (gusset bottom) 362712cm (Lining fabric) 100% polyester (Part of the filling) Polyethylene Bag opening zipper opening The wide open zipper makes it easy to see what's inside. The sash and backrest are well cushioned to avoid putting strain on your shoulders when you carry it on your back. Even with heavy loads, the weight is easily distributed and you can carry the backpack with good balance.