The karrimor refuel 20 5 daysack is a lightweight hydration bag designed for running cycling and walking and comes with a 2 litre hydration system to ensure that you are kept hydrated while you are on the go the refuel range is available in different sizes and this lightweight 20 5 bag has been kept simple to keep the weight and bulk to a minimum and is ideal for taking just a few essential things along with your hydration pack when you are enjoying a run or a cycle ride as there is a main zip