The new Caffewerks puck screen can help soften and even the delivery of water to the coffee bed and help prevent channeling and to ensure a more even and balanced extraction. The 53mm fits 800 Series Breville Espresso Machine portafilters. The puck screen is added as a final step on top of your tamped espresso bed, before starting your extraction. Breville Espresso Machines 53.3mm 53.3mm diameter 1.7mm thick 150 micron filtering made of Sintered 316 Stainless Steel Not sure which size or part you need? All Espresso Machine Parts are non-returnable. If you aren't sure what part you need please send us a message in the contact box below and we will help get you set up for success!