Function: 1. 18pcs in 1 set: The set includes 18pcs ER32 spring bushings, the application range is 3-20mm to meet different fastening needs. 2. Made of carbon steel: made of excellent carbon steel material, with high hardness and wear resistance, can be used for a long time. 3. Good performance: These spring bushings have high clamping force, high accuracy, wide clamping range and high practicality. 4. Multiple applications: suitable for CNC, engraving machine and other equipment, used for milling, boring, drilling, wire threading and other operations. 5. With storage: These collets are placed in the storage compartment, which is convenient for storage and access at any time. Specification: Item Type: ER32 Spring Sleeve Clamp sleeve material: stal carbon Wooden box Material: laminated wood Product Model: ER32 Product height: approx. 40mm / 1.6 inch Product diameter: approx. 33mm / 1.3 inch Use range: approx. 3-20mm/0.1-0.8in Scope of application: suitable for CNC, engraving machine and other equipment. Used for milling, boring, drilling, tapping and other operations List of packages: 18 x spring clamp1 x storage compartment