This product is a 1pc ER Spring Collet Chuck designed for CNC milling and engraving machine spindles. It supports multiple ER sizes and delivers precision tool holding with tight tolerance, making it a versatile choice for precise machining tasks. Key benefits Wide compatibility: works with ER11, ER16, ER20, ER25, ER32 collets, providing flexible use across common ER sizes. precision clamping: achieves tight tolerance with 0.005 mm to 0.008 mm accuracy, reducing runout and improving finishing quality. Reliable tool retention: spring collet design provides firm grip on tools, enhancing machining stability and consistency. Easy integration: compatible with standard CNC milling tool holders and engraving machine spindles, enabling straightforward swap and setup. Singular, compact solution: supplied as 1 piece for convenient use in small workshops or production environments. Key attributes Functionality: spring collet chuck for CNC milling and engraving applications Compatibility: ER11, ER16, ER20, ER25, ER32 ER sizes; suited for ER2513mm spindle configurations Size range: covers multiple ER size applications through a single collet chuck design Material and build: designed as a spring collet chuck (specific material not stated) Performance: precision clamping with 0.005 mm to 0.008 mm accuracy to minimize runout Two to three practical use cases Precision engraving: secure carbide or steel engraving bits with minimal runout to produce clean, detailed lettering on metal surfaces. Smallpart CNC milling: clamp small end mills or drill bits across ER sizes for consistent pocketing and contouring on delicate parts. Jewelry and watchmaking: hold fine cutting tools with positional accuracy for delicate material sculpting and fine detail work. This description maintains the brand's specification and features, presenting a clear and professional overview that highlights why this ER spring collet chuck is a valuable addition to CNC milling and engraving setups.