51/53/58mm Reusable Coffee Filter Screen Heat Resistant Mesh Portafilter Barista Coffee Making Puck Screen for Espresso Machine

The main purpose is to prevent the impact of high-pressure hot water on the coffee powder, causing the surface of the powder to crack.The cracked powder will produce a lot of "floating" subdivisions, which is easy to over-extract and produce miscellaneous flavors, and it will stick to the upper water separator after extraction.