1、Pressure Relief Mechanism: This 58mm blind filter is designed for backflushing semi automatic coffee machines with a pressure release mechanism. Make sure your coffee machine has a suitable pressure release valve and that the diameter matches correctly. 2、Stainless Steel Construction: Made from premium stainless steel, this blind filter is rust resistant, durable, and long lasting, ensuring a reliable performance over time. 3、Fits Standard Group Handle: The insert basket easily fits into the group handle of your coffee machine, replacing the standard filter for backflushing purposes. 4、Easy to Clean: This stainless steel portafilter blind filter can be easily cleaned by rinsing it with water, making the cleaning process simple and convenient. 5、Effective Coffee Residue Removal: Backflushing with a blind filter helps remove coffee residue accumulated in the coffee head. It can be used in conjunction with cleaning agents for optimal results.