This Plunge mixer is the top of the line of heavy-duty mixers. It has a 3 3/16 inch diameter mixer head blade that fits 3 - 7 gallon pails. The shaft is 22 inch and can be used with a 1/2 inch drill. The mixer itself is zinc-aluminum which is more durable and has a longer life than pure aluminum. Round-style mixers are ideal for dry materials, heavy coatings, glues, printing ink, resins, plaster, cement, and more.