The pack itself has a 5 litre capacity, to allow you to carry the usual spare necessities, such as spark plug, tube, tools etc.  It has a removeable pocket and pouch for your toolbag.

The water bag has a 2 litre capacity, and is easy to clean as it has a large cap.  The drinking straw area has an adjustable opening and closing valve.

The bag has X Braces with central quick release, which you can adjust to fit you, as it has 4 Velcro straps.

The fabic is breathable in the area which comes into contact with your back.