A messenger bag is a type of sack, usually made out of some kind of cloth, that is worn over one shoulder with a strap that winds around the chest resting the bag on the lower back. Messenger bags are often used by bicycle messengers, though they are now also an urban fashion icon. Similar function to backpacks, messenger bags ensure comfort to people carrying heavy and bulky items, while allowing easy access to the contents. Messenger bags typically incorporate features that make them particularly suitable for cycling, such as fittings that make it easy to adjust the shoulder strap, quick release buckles, an adjustable hinged buckle, and the ability to attach a variety of accessories, such as lights, phone holsters, or U-locks. Contemporary stabilizing straps help to prevent the bag from shifting while riding. Many college and high-school students make use of them for fashionable and functional purposes, especially those who commute on bicycles. Compared to a backpack, it is much easier to place and remove text-books, notebooks, essays and supplies from a messenger bag because they lie on the side of the body, granting the wearer better accessibility. Messenger bags also provide more weather resistance than traditional leather satchel- style school bags.