The blades fold down allowing for easy insertion into a barrel or even a glass carboy. Ideal for mixing, stirring wine and works great as a degasser. As soon as you turn your drill on the blades expand to create a powerful stirring action. We do not recommend using in a carboy that is topped full because the stirrer displaces too much liquid and also creates a vortex that will send wine out the top. In these cases a hollow racking cane works exceptionally well. Works with 3/8" or larger drills.