This 54mm Bottomless (Naked) Portafilter is designed to work with Breville / Sage Barista Series BES880, BES878, BES875, BES870, BES840, BES810, BES500, Barista Express, Barista Touch, Barista Pro, Infuser, Duo Temp pro. Made of high quality food grade stainless steel and solid ABS; the ABS handle looks great and is comfortable to hold. With this 54mm espresso bottomless portafilter, you'll be able to see the extraction in real time to understand if you're grinding and tamping correctly. Detachable design, convenient and quick to disassemble, easy to use, and easy to clean. BASKET NOT INCLUDED, Coffee Magenetic Dosing Funnel Included - If you want to improve your barista skills by using a visual aid to identify what you're doing wrong, this is the perfect tool. FIRSTENJOY 54mm Stainless Steel Bottomless Portafilter What is a bottomless portafilter and what is it used for? Bottomless portafilters are used as a training tool. It will provide you with immediate feedback and can see if channeling occurs right away. Channeling is the rapid passage of water through fractures in the coffee puck, which produces a thinner, under-extracted espresso. When it occurs, you'll often see sudden appearances of blond streaks in the stream of espresso; sometimes the puck will even have pencil lead-sized holes where channeling occurred. With this 54mm naked portafilter, you'll be able to see the extraction in real time to understand if you're grinding and tamping correctly. If you want to improve your barista skills by using a visual aid to identify what you're doing wrong, this is the perfect tool. Make sure this fits your model number - Breville BES870XL Barista Express Espresso Machine - Breville BES870BSXL Barista Express Espresso Machine - Breville BES878BSS Barista Pro Espresso Machine - Breville BES880BSS Barista Touch Espresso Machine - Breville BES840XL Infuser Espresso Machine - Breville BES500BSS Bambino Plus Espresso Machine - Breville BES810BSS Duo Temp Pro Espresso Machine Specification: Item Type: 54 mm Bottomless Portafilter with ABS Handle Material: 304 Stainless Steel + ABS Weight: 0.73lb Package includes: 1 x 54mm Bottomless Portafilter (BASKET NOT INCLUDED) 1 x Coffee Magenetic Dosing Ring Note: * DOES NOT WORK with 58MM Breville Dual Boiler, Oracle or Oracle Touch.