Compatibility and purpose: Designed for Dongling 51mm threeear espresso machines, this aluminum alloy bottomless portafilter holder provides a precise fit and stable performance to help you brew baristastyle espresso at home or in a café setting. Durable construction: Features a sturdy aluminum alloy head paired with a comfortable plastic espresso handle, delivering dependable performance over time while resisting wear from daily use. Secure threeear design: The tripleear structure ensures a tight lock with your machine, preventing leaks and guaranteeing a consistent water flow for rich, balanced extraction every time. Easy cleaning: Rinse under running water after use for effortless upkeep, helping you maintain hygiene and spend more time enjoying smooth, aromatic espresso with minimal effort. Use scenarios: Home daily espresso: Ideal for home baristas seeking consistent extractions with a bottomless portafilter setup. Small café or kiosk: Reliable performance during busy service with a secure fit on a Dongling 51mm threeear machine. Training or latte art practice: Bottomless design enables visibility of flow and channeling, aiding skill development and quality control.