Factory ground OEM bottomless portafilter from La Marzocco.
La Marzocco makes these portafilters out of chrome plated brass. We use a Strada 21 gram basket in ours and love the results. Bottomless portafilters allow the barista to visually assess how evenly the coffee extracts through the basket. Imperfections in dosing and tamping technique are exposed when the coffee spurts out in different directions instead of straight down into the cup. This is known as channeling. It can be a little messy to start with but is an invaluable learning tool for any espresso aficionado.
*Basket not included*