If you want to dispose of the coffee grounds after preparing your fragrant favorite hot beverage, you don't want to awkwardly walk to the trash can with the hot portafilter. Simply place the knock box space-saving next to your portafilter coffee machine and gently knock the coffee grounds against the rubberized bar directly from the portafilter. The high capacity of the drip box is just as practical as the non-slip rubber ring at the bottom.