Whether you are heading out for a day of sight-seeing walking cycling or going to school or work this Vango Stone 20 Daysack is an incredibly versatile rucksack that has 20 litres of capacity across two useful pockets one with an organiser pocket & key chain & is hydration compatible making it a fantastic choice of rucksack for everyday use The Stone 20 Rucksack has an Air Force back system that has a contoured air channel & has Air Mesh on the contact points as well as on the rucksack straps to allow air to flow & keep you nice & comfortable while carrying this pack making it a great bag to take with you wherever your day takes you