Intended for day trips. The capacity is usually 20 to 30 liters. The smallest daypacks will not hold much more than rain gear and some food and drink; the larger ones can hold an extra sweater and a first aid kit, for example. A daypack always has two shoulder straps and usually no (or only very thin) hip straps. So you carry the entire weight on your shoulders. Those who get shoulder pain easily may consider purchasing a Hiking Backpack with hip straps.