The present invention relates to the pockets (10) that can accommodate fluid, the fluid includes at least two compartments (11,12) and at least two export (13,14), each to export each compartment (11 being connected in the compartment (11,12), 12) pipe (15 in, 16), which is characterized in that compartment (11) has the geometry for optimizing the fluid. The volume of pocket (10), to prevent maximum acceptable pressure from collapsing.
