About this item HIGH QUALITY MATERIAL: Made of rubber, durable in use, and avoid scratch your portafilter or your hand. PERFECT SIZE: 4 X 4 Inch (D*H). It's perfect for most espresso machines. With enough capacity, it could prevent coffee grounds from splashing all around. MULTIPURPOSE: It could be widely used in coffee shop, western restaurant, bar, home kitchen etc. EASY TO CLEAN: You can clean it by hand, dishwasher safe, save your time on the washing the coffee tool. 100% MONEY BACK GURANTEE: If unfourtunately your Mini Knock Box did not work smoothly, please feel free to contact us for exchange or refund.