Cotton liningZipper closureHEAVY DUTY CLEAR BACKPACK: Made of 0.6mm water-resistant PVC plastic, which is 70% thicker than clear backpacks on the market. Fully transparent design allows visibility of items for security checkpoints in schools or at work EXTRA STRONG SEAMS: All seams are double stitched and the stitching around the shoulder straps are reinforced. This transparent school backpack is reliable for carrying heavier loads, such as books and a laptop REINFORCED PADDED STRAPS: The shoulder straps are padded with thick cotton to reduce pressure when carrying heavier loads. Shoulder straps are adjustable from 16 to 31 and maximum weight is 66 lbs. LARGE CAPACITY: Overall external size is 17 x 15 x 8. 1 large main compartment with laptop sleeve can hold laptop up to 39at 15.6, 1 front zippered pocket with mesh slots for storing phone, pens, keys, etc., 1 side zippered pocket for frequently used items, 1 stretch mesh side pocket for large bottles or umbrella LARGE CAPACITY: The exterior overall size is 16 x 13.8 x 6.3. 1 large main compartment with laptop sleeve that can hold up to 15 laptops, 1 front zip pocket with mesh slots for storing phone, pens, keys etc., 1 side zip pocket for frequently used items, 1 stretch mesh side pocket for large bottles or umbrella