This 58mm Bottomless (Naked) Portafilter is designed for use with the Breville BES900XL, BES920XL, BES980XL, and BES990BSS Dual Boiler Espresso Machines. The bottomless design allows you to observe the espresso extraction in real time, helping you evaluate your grinding and tamping techniques. Featuring a detachable construction, it is easy to disassemble, use, and clean. BASKET NOT INCLUDED. This portafilter serves as a training tool, providing immediate visual feedback to identify issues such as channeling. Channeling occurs when water forces its way through cracks or weak spots in the coffee puck, resulting in uneven extraction and a weaker, under-extracted shot. With this naked portafilter, signs of channeling—such as uneven flow or blonding in the espresso stream—can be clearly seen, allowing for adjustments to improve shot quality. Ideal for home baristas looking to refine their espresso-making skills, this 58mm bottomless portafilter offers a practical way to achieve more consistent results. Color: Black + Silver Material: Alloy + Plastic Item Type: 58mm Bottomless Portafilter Weight: 0.73 lb Package Contents: 1 x 58mm Bottomless Portafilter (Basket Not Included) Note: This product is compatible only with the specified Breville Dual Boiler models. The package includes only the portafilter; other items shown are not included. Due to lighting and display differences, actual product color may vary slightly from images. Measurement may vary by +/- 1-3 cm.