51mm dosing funnels by MATOW 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. A premium accessory for a premium experience. The 51MM dosing funnel (compatible with all 51mm portafilters) is a must-have to perfectly grind your coffee without mess or waste. With a magnetic base, stability is ensured in any portafilter inclination. THIS SPECIFICS : Materials?304 stainless steel + Magnetic Steel Width? Fits 51mm portafilters Weight?78 g Product Height: 0.7in (18mm) Outer Ring: 2.6in (66mm) Inner Ring: 1.95in (49.5mm)