1. Wide compatibility This coffee knock bin is compatible with most 51mm, 53mm, 54mm, and 58mm portafilters, making it suitable for a wide range of espresso machines. 2. Durable construction Made of durable materials, this knock box is thick and dense, resistant to cracking, deformation, heat, and wear, providing longlasting durability. 3. Easy to clean Featuring an embedded design and detachable structure, the coffee grounds box can be easily cleaned with minimal effort, allowing for convenient removal of coffee powder. 4. Secure and quiet Constructed with thickened iron and a silicone protective rod, this knock box offers stability and safety during use, reducing noise when tapping the powder. Use scenarios Home espresso setup: after pulling shots, quickly knock out used grounds into the box to keep the workstation tidy. Small cafe or office: robust construction supports daily use with reduced noise for a more comfortable counter environment. Busy bar or counter: easy cleaning and stable design help with quick cleanup between rounds.