Premium Material: The coffee dosing ring is made of high-quality 304 stainless steel, which is rust-proof, corrosion-resistant, and food-grade, ensuring the health of your family. Flared Mouth: The flared mouth of the coffee dosing funnel effectively prevents coffee grounds from scattering on the table during grinding. The coffee dosing ring is a very convenient espresso accessory, preventing coffee waste and keeping your workbench clean. Fits 53.35mm Portafilters: The coffee dosing funnel fits most 53/54mm diameter portafilters on the market. (Note: Remove the dosing ring before tamping!) Easy to Clean: Simply rinse the portafilter funnel with water and clean it with a brush or sponge. To use, place the funnel on top of the portafilter, grind, distribute, and tamp, then quickly remove the funnel when finished.