The S/S mix stir has been designed with longer stainless steel (S/S) rod 22 inches long. It's unique blades act like a turbine for maximum mixing and stirring efficiency. The plastic blades are safe to use with glass carboys. The S/S mix mix stir allows you to use any size bung that fits your carboy if you want to use a bung. Constructed with 100% food grade material.