This 58mm bottomless (naked) portafilter is designed for use with Breville BES900XL, BES920XL, BES980XL, and BES990BSS Dual Boiler espresso machines. The bottomless design allows you to observe the extraction process in real time, helping you evaluate your grinding and tamping technique. It features a detachable construction for easy disassembly, use, and cleaning. Basket not included. This portafilter serves as a training tool, providing immediate visual feedback during extraction. It enables you to detect channeling, which occurs when water forces its way through cracks or weak spots in the coffee puck, resulting in uneven extraction and weaker espresso. Signs of channeling include early blonding in the espresso stream or small holes in the used coffee puck. Ideal for improving barista skills, this 58mm naked portafilter helps identify inconsistencies in preparation methods through direct visual assessment. 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 portafilter is compatible only with the Breville BES900XL, BES920XL, BES980XL, and BES990BSS Dual Boiler espresso machines. The package includes only the items listed above. Due to lighting and display differences, the actual product color may vary slightly from images. Measurement may have a 1–3 cm variation.