Product description 1.58mm stainless steel bottomless filter holder designed for 58mm portafilters with a wooden handle. This accessory fits 58mm portafilter machines and adds a bottomless design for enhanced visibility during extraction. Material and build: made from stainless steel with a thickness of 1.58mm, offering durability and reliable performance for everyday use. The wooden handle provides a comfortable grip and a classic look. Function and benefits: bottomless design allows you to observe the espresso extraction in real time, helping identify channeling and flow irregularities. This makes it easier to adjust grind size, dose, and tamping technique to improve shot quality. Compatibility and specifics: compatible with 58mm portafilter groups. Note: 58MM3 ear coffee machine handle. Performance advantages: clear visibility of shot progression, aiding quality control and skill development for home users and professional baristas alike. Well suited for training, troubleshooting, and optimizing espresso results. Use scenarios Home espresso setup: use the bottomless filter holder to monitor extraction, learn how grind size and tamping affect flow, and fine tune your routine. Barista training or cafe environment: demonstrate shot flow and diagnose channeling with students or staff, supporting precise technique improvements. Equipment upgrade or maintenance: a conventional filter holder on a 58mm system to gain observation capabilities and refine extraction without changing other equipment.