- 54mm naked/bottomless portafilter: 54mm portafilter head is designed to fit Breville the Barista Express, Barista Pro, Barista Touch, Bambino Plus, Infuser and Duo-Temp Pro. - Extraction improvement: A bottomless 54mm portafilter lets you see the extraction clearly, helping you identify and correct issues related to grind size or tamping. It is a valuable tool for both beginners and experts. - Ergonomic design: The handle is made from natural sandalwood for a comfortable, secure grip. The portafilter head is cast in food-grade stainless steel and hand polished; its precise size ensures a firm engagement with the group head. - Important note: These portafilters are designed to fit snugly into the espresso machine group head to provide a tight brew seal. Tolerances vary between machines, so some may fit more snugly than others. If you experience fitment issues, please contact our team. - Practical use scenarios: • Troubleshooting a shot at home by observing flow and adjusting grind or tamp to improve consistency. • Training sessions to demonstrate proper tamping and distribution and to dial in grind size visually. • Quick pre-service check to verify consistent extraction before serving guests.