The 58 mm Bottomless Portafilter is a great tool for ensuring consistency in your dosing and tamping. You can easily see if channeling is occurring during brewing, or if you've tamped at an angle, which results in a bad shot.
These portafilters are made from the Rancilio portafilters used on commercial machines. The basket is a commercial-quality La Marzocco triple basket, which can hold 19-21 grams of espresso, perfect for pulling a Portland style triple ristretto.
This Bottomless Portafilter fits not only the Rancilio Silvia, but also the Andreja Premium, Anita, Alexia, Vetrano and the Alex II.