About This Precise 51mm Fit – Designed for 51mm portafilter baskets to ensure a snug, accurate fit with compatible home espresso machines. Consistent 30lb Pressure – Built-in calibrated spring delivers uniform tamping force every time for optimal extraction. 100% Flat Stainless Steel Base – Durable, rust-resistant, and easy to clean for long-lasting performance. Ergonomic Palm Handle – Comfortable grip design reduces wrist fatigue during repeated use. Professional Results at Home – Creates an even coffee bed, reduces channeling, and enhances crema, aroma, and flavor.