Impeller for bioprocessing

An impeller for a biocontainer comprising:

• (a) a hub including a top end and a bottom end, and at least first and second impeller arm slots arranged vertically and extending from the top end toward the bottom end;
• (b) at least first and second impeller blades extending from the hub, each impeller blade comprising a blade face, an arm having a first end and a second end and a notch between the first end and the second end, wherein the first end is adjacent to the blade face, and the second end extends into an impeller slot, the arm being engaged in the slot, and wherein the second end of the first impeller blade arm engages with the notch of another impeller blade arm.