Breville Knock Box MiniBreville Knock Box Mini Breville's Knock Box Mini provides the same quality, durability and reliability as it's original Knock Box, but in a more compact format! Simply tap the port filter against the rubberized knock bar to loosen even the most intensely compacted coffee puck. The stainless steel canister and no slip rubber grip ensure stability, while the rubberized knock bar ensure that even the firmest knocks will not damage, ding, or dent your