A mixer engagement system comprising: an agitator comprising: (a) a rotatable impeller comprising two or more blades, two or more magnets, and a shaft, wherein the impeller is configured to be driven by a drive unit magnetically coupled to the impeller; (b) an impeller seat receiving the rotatable impeller, the impeller seat comprising an upwardly arranged cylindrical housing, a flange, and a base, the cylindrical housing comprising a central opening for the impeller shaft, and the base comprising a collar characterized in that (b') the base further comprises at least 3 pins (230A, 230B, 230C) arranged to engage with a locking and centering mechanism; and in that the mixer engagement system further comprises the locking and centering mechanism; (c) the locking and centering mechanism comprises a rotatable hollow cylindrical housing comprising at least 3 angled slots (330A, 330B, 330C) configured to receive the pins (230A, 230B, 230C) of the impeller seat, each slot (330A, 330B, 330C) comprising an open end (331A, 331B, 331C), a downwardly angled channel (332A, 332B, 332C), and a closed end (333A, 333B, 333C); and (d) a lever is mounted to the rotatable hollow cylindrical housing, wherein, when the impeller seat is placed in contact with the locking and centering mechanism, with the pins (230A, 230B, 230C) in the open ends (331A, 331B, 331C) of respective slots (330A, 330B, 330C), and the lever is in a first open position, movement of the lever from the first open position to a second closed position rotates the rotatable hollow cylindrical housing such that the pins (230A, 230B, 230C) move downwardly in the slots (330A, 330B, 330C) along the downwardly angled channels (332A, 332B, 332C) to the closed ends (333A, 333B, 333C), locking the impeller seat into a fixed and compressed position. (a) a rotatable impeller comprising two or more blades, two or more magnets, and a shaft, wherein the impeller is configured to be driven by a drive unit magnetically coupled to the impeller; (b) an impeller seat receiving the rotatable impeller, the impeller seat comprising an upwardly arranged cylindrical housing, a flange, and a base, the cylindrical housing comprising a central opening for the impeller shaft, and the base comprising a collar characterized in that (b') the base further comprises at least 3 pins (230A, 230B, 230C) arranged to engage with a locking and centering mechanism; and in that the mixer engagement system further comprises the locking and centering mechanism; (c) the locking and centering mechanism comprises a rotatable hollow cylindrical housing comprising at least 3 angled slots (330A, 330B, 330C) configured to receive the pins (230A, 230B, 230C) of the impeller seat, each slot (330A, 330B, 330C) comprising an open end (331A, 331B, 331C), a downwardly angled channel (332A, 332B, 332C), and a closed end (333A, 333B, 333C); and (d) a lever is mounted to the rotatable hollow cylindrical housing, wherein, when the impeller seat is placed in contact with the locking and centering mechanism, with the pins (230A, 230B, 230C) in the open ends (331A, 331B, 331C) of respective slots (330A, 330B, 330C), and the lever is in a first open position, movement of the lever from the first open position to a second closed position rotates the rotatable hollow cylindrical housing such that the pins (230A, 230B, 230C) move downwardly in the slots (330A, 330B, 330C) along the downwardly angled channels (332A, 332B, 332C) to the closed ends (333A, 333B, 333C), locking the impeller seat into a fixed and compressed position.