Model F 58mm Bottomless Portafilter Filters (2 Pack) Includes two 58mm bottomless portafilter filters designed for standard espresso machines. This professional accessory helps baristas and enthusiasts observe shot extraction directly and diagnose issues in real time. The twofilter set provides a ready replacement or backup for busy environments. Key benefits Realtime extraction visibility: the bottomless design lets you observe pour flow, evenness, and potential channeling, making it easier to adjust grind size, dose, and tamping technique. Quick diagnostics and training: ideal for coaching baristas or refining technique, enabling precise feedback on shot quality without removing the portafilter. Practical, timesaving setup: with two filters in the package, you can swap between shots or keep a clean filter ready while the other is in use or being cleaned. Key attributes Functionality: bottomless (naked) portafilter filter for direct observation of espresso extraction. Compatibility: designed for 58mm portafilter baskets; suitable for espresso machines that use a 58mm group head standard. Size: 58mm diameter filter insert. Material: material not specified in the listing. Performance: enables straightforward visualization of pour dynamics to aid parameter tuning and quality control. Use cases and applications Home espresso setup: use during grind and dose experiments to quickly identify channeling or uneven flow and adjust accordingly. Training and coaching: demonstrate proper tamping and extraction technique to students or team members by showing shot flow in real time. Cafe workflow optimization: have a backup bottomless filter on hand for rapid swap during busy service, while the other is cleaned or prepped for the next round. Notes Model designation: F (as indicated by the product title). Package quantity: 2 pieces (two bottomless filters). This description reflects the product's stated features and intended use, focusing on the benefits of a 58mm bottomless portafilter accessory and its relevance to both home and professional espresso preparation.