to haul or hang the backpack portion 50 of course other types of buckles and fasteners also may be used 0029 fig5 illustrates a rear view of the backpack portion 50 which may be attached to the hydration pack portion 10 according to the embodiment shown in fig4 slots or openings 86 88 receive the shoulder straps 28 30 airlock buckles 90 92 attach the shoulder straps 28 30 to the backpack portion 50 when the user wishes to utilize both the hydration pack portion 10 and the attachable backpack portion 50 a hip belt 94 fits around the user 39 s waist for securing the backpack 50 to the user other buckles and straps could be used for this purpose therefore if the user wishes to use the hydration pack portion 10 separately i e without attaching the backpack portion then the user simply attaches the shoulder straps 28 30 by way of the male airlock buckle 46 on each shoulder strap 28 30 to the airlock buckles 32 34 on the other hand if the user wishes to attach the backpack portion to the hydration pack portion 10 for additional carrying space then the user detaches the shoulder straps 28 30 from the airlock buckles 32 34 on the hydration pack portion 10 slides the shoulder straps through slots 86 88 on the backpack portion 50 and fastens the shoulder straps 28 30 to the airlock buckles 90 92 on the backpack portion 50 in this way the hydration pack portion 10 may be used either as its own pack or may easily be received within the attachable backpack portion so that additional carrying space is provided a unique feature of the invention therefore is that the shoulder straps 28 30 are attachable either to the hydration pack.