Specifications: This 58mm bottom diameter blind filter is used for backflushing on semi-automatic espresso machines with a pressure release mechanism. It is suitable for use as a group handle in place of standard filters. Backflushing the coffee maker helps to remove the built-up coffee residue inside the set head. Blind filters can be used with cleaning tablets. Type: Blind Filter Material: Metal Function: Mini, Coffee Machine Supply Non-porous coffee machine filter cup, blind bowl, can be washed repeatedly blind cup bowl Product size: about 5.8 cm/2.28 inches Quantity delivered: 1 piece Note: Due to differences in lighting and screen settings, the color of the item may be slightly different from the picture. Please allow for slight size differences due to different hand measurements.