General description 3Pcs HSS Collet Chuck Head set includes three different chuck heads (6 mm, 6.35 mm, and 8 mm) designed to meet various woodworking needs. Made from high-speed steel, these chucks are durable, wear-resistant, and provide stable performance. Technical specifications Chuck sizes: 6 mm, 6.35 mm, 8 mm Material: High-speed steel Usage Suitable for engraving machines Compatible with wood routers Works with trimmers and vertical routers