Pouch for components of a system has pockets

The invention relates to a protective case (18) for components of a system pockets for the treatment of a biological fluid, said bag system being composed of at least one filtration unit (2) of the biological fluid , said protective case (18) including a cavity having a first volume intended to receive said filter unit (2) and at least one second volume, said cavity being formed between a base member (19) and a cover member ( 20) removably disposed on said base member (19), means for holding the filter unit in said first volume being arranged in said cavity, said holding means being adapted to prevent movement of the unit of filter (2) inside the protective case (18) when said filter unit (2) is arranged in said holding means.