Simply twist the funnel onto your 58mm portafilter, aligns the funnel with the grinder, gently press forward to engage the auto-grinder, and release Made of quality aluminum alloy material, this adapter rings is and can withstand high pressure and frequent use, guaranteeing a long lifespan Perfect for coffee enthusiasts who seek to control the extraction and taste of their coffee by replacing the tamper base Perfect for coffee grinding, avoid spillages, no more mess and spil over grind This espresso dosing funnel helps collect and tamp all of your coffee grounds in your 58mm portafilter with ease, the grounds can be tamped without removing the dosing funnel