The 58MM Coffee Portafilter Bottomless Filter Accessory, model G, is a purpose built insert designed for 58mm portafilter handles. Its bottomless design provides a direct view of espresso flow as it exits the portafilter, enabling real time inspection during extraction. Key benefits Visual feedback during extraction helps you observe grind size, dose, distribution, and tamping consistency to improve overall shot quality. The bottomless design makes channeling and uneven flow immediately apparent, allowing faster troubleshooting and adjustment. An effective training aid for and experienced users alike, supporting technique development and workflow optimization. Simple integration with existing 58mm portafilter setups, enabling quick adoption without changing equipment. Key attributes Size: 58mm Design: Bottomless filter for direct extraction visibility Model: G Function: Coffee machine accessory for standard 58mm portafilter handles Compatibility: Intended for use with 58mm portafilter systems Use cases Home espresso setup: monitor flow and make precise adjustments to grind, dose, and tamp for better shots. Barista training: teach proper distribution and tamp technique by observing extraction from a naked portafilter. Small cafe quality control: visually inspect espresso flow to identify and address channeling or inconsistencies in the shot.