ECM Knock Out Box RoundMade out of brushed stainless steel, ECM's round knock box features a sound absorbing knock bar to cut down on noise as you knock out pucks from your portafilter. The knock box rests on a set of rubber feet to prevent slipping and the knock bar is removable for easy cleaning. Knock boxes help to eliminate mess on your countertops and eliminate the hassle of removing spent coffee pucks.