Camelbak Blowfish Hydration Pack

This is a versatile, expandable, hydration system that can be zipped up into a sleek, low profile, summer system, or, within seconds the main compartment can be expanded to created 5 litre's of extra space, for stashing extra layers in the winter.
It has a 3.0L bladder and a 7.9L - 12.8L (expanded) cargo capacity, with 2 useful front pockets with an organiser plus an internal mesh pocket and pump holder.
It is held in place by a removable waist belt and a sliding Sternum strap and has a zipped back panel.