This is a magnetic attachment specifically for the Comandante C40/C60 grinder. One of the drawbacks of the Comandante is the removal of the jar, or the grounds receiver. This attachment makes it easy to remove by twisting. Magnets are arranged for easy removal. Also, after long use, the magnets may come off due to their strength, but they can be easily repaired with glue, so you can use it for a long time. You can choose from black or brown in the photos. We can also accommodate other colors to some extent if you specify, so please consult with us. How about it? ^_^