Constructed from polished stained steel, this knockbox is an ideally handy and life-simplifying device for your espresso experience: a knockbox offers an elegant way to extract spent grounds from your portafilter. The knock bar is covered with rubber to reduce damage to the filter holder. The thick rubber base prevents the knockbox from sliding and reduces the noise level. We recommend it for home use. It works with both home and commercial filter holders, but being small and compact, its volume is not ideal for commercial use.