Overflow ControlOur dosing funnels are specifically designed to help eliminate the overflow of coffee grinds while dosing into your portafilter. Eliminating overflow helps you reduce mess, waste, and in turn, will result in much more consistent dosing weights. Our 58mm espresso dosing funnels are designed to work with a wide variety of portafilters on the market today, including Breville/Sage Dual Boiler, Breville Oracle, Rocket, Flair 58, and many more.IMPORTANT NOTE: When using machines such as the Breville/Sage Barista Express, the portafilter holder (used to hold the portafilter when dosing/grinding) cannot be used while the funnel is installed.