This resembles an immersion blender but instead of a propeller-like blade at the end, it has a fixed tube with a rotor that spins within it. With settings up to 30,000 rpm, rotor stator homogenizers can create emulsions mechanically, sometimes without any emulsifier in the recipe. For example, a vinaigrette with no mustard made using a rotor stator homogenizer remains stable for days. The device is invaluable for making emulsified sauces such as mayonnaise, hollandaise, beurre blanc, and other stubborn emulsions.