Review on Dremel Multi Tool Replacement Coupling 2615294309 5PK by Rovy Oppeneer

YES! THIS FITS DREMEL MODEL 420. This item is known as a coupler. They are supplied in packs of 5 and must be replaced when using this range of Dremel tools. Replacement is quick and easy, don't think your tool is broken! If your tool's motor is running but the collet head is not spinning, unplug the tool from the power source, remove the screwdriver, and open the tool. If you see a few small pieces of chewed plastic, you need this part as a replacement. It connects or couples the motor to the collet shaft. My tool is over 30 years old and has at least 1,000 hours on it and this was the first time I've replaced a clutch. When replacing the clutch, it would be a good idea to also install new brushes on the motor and use a can of compressed air to clean the frame or the plastic parts that hold everything together nicely.