The bag with a variable amount of pocket space. Have you ever been stuck in a hand luggage debate with a budget airline? Well if this one gets any complaints you can tighten the side strap and squeeze it smaller - just dont squash anything delicate! Space for your tablet and laptop too, i-stay covers all the bases. You know what we hate about regular bags? They dont stay put! And they arent even commended by The Royal College of Chiropractors. I mean the straps on this bag are award winning and even have had the Royal stamp of approval, if the Queen of Chiropractors wants it then why dont you? All i-stay backpacks come with the patented dual i-stay strap, which is commended by The Royal College of Chiropractors for its sound ergonomic design and for the health benefits likely to be gained from using the products.