The present invention relates to a coupling system intended more specifically to the fitting and attaching of additional and removable internal baskets defining isolated washing rooms in clothes washing machines. Such a system is intended more particularly to clothes washing machines (1) comprising a cabinet (2) within which it is located a fixed tank (3) with which cooperate a washing basket (4), a balancing device (5), a removable washing compartment (6) and an stirrer element (7), characterized by the fact that the balancing device (5) comprises at least one surface comprising a plurality of coupling members (51) and the removable washing compartment (6) cooperates with the balancing device (5), wherein said removable washing compartment (6) comprises at least one surface comprising a plurality of coupling elements (61) cooperating with the elements coupling (51) of the balancing device (5).