Features: Made of 304 stainless steel, it is labor-saving, corrosion-resistant, easy to use, and does not take up space. This 58 mm blind filter is used for backwashing on semi-automatic espresso machines with pressure release mechanism. It is installed in the group handle and replaces the standard filter. Backwashing the coffee machine helps to remove the coffee residue that has accumulated inside the coffee machine for head. The blind filter can be used in conjunction with the cleaning sheet. Please make sure that your coffee machine is equipped with a suitable pressure relief for valve and the diameter is suitable for your coffee machine. for Always follow the manufacturer's cleaning instructions. Specifications: Material: Stainless Steel Weight: 20g Outer Diameter: 7cm/2.76inch Color: Silver Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Backflush Insert