This is a backpack purchased for business use. It has been used a few times, but there are no noticeable stains. It can be used in 3 ways: as a backpack, as a vertical tote bag, and as a horizontal tote bag. Gusset expansion - 68% increase. The gusset can be expanded by 12cm, allowing for storage of 22L items before expansion and 37L items after expansion. It can store a 15.6-inch laptop, a 9.7-inch iPad, A4-size documents, and 3-5 days' worth of clothing. There are many pockets inside and on the back (back part), making it convenient for storing small items. There are no noticeable stains, and the adhesive tape on the PC storage section can be used without any problems. Thank you. Size: 48x32x17cm (before expansion: 22L) / 48x32x29cm (after expansion: 37L) Weight: 1.4kg Shoulder strap length: Shortest approx. 47cm ~ Longest approx. 93cm (* from the top base to the bottom base) / Width approx. 8cm. Remarks: Waterproof With USB port