The Best Portafilter Partner The HCS 58mm dosing funnel helps espresso grounds land directly into the portafilter, keeping your workspace spotless. Dosing funnel is magnetized at the bottom allowing for a strong hold on your portafilter during the grinder process. The dosing funnel also helps keep your countertops clean during puck prep as well! Specifications Designed to work with 58mm portafilters ;