This 18PCS/Set ER32 Spring Collets Set includes a range of sizes from 3-20mm, suitable for various machining needs. The set comes with an MT3-ER32 Collet Chuck and ER32 Spanner, making it convenient for use on milling machines and machining centers. The unbranded/generic collet chuck model is reliable and efficient for metalworking tasks, providing a secure and stable grip on workpieces for precision machining. With custom bundle options, this set is designed to meet the specific requirements of professionals in the CNC, metalworking, and manufacturing industries.