Item Type: Router Collet Adapter_x000D_Material: Carbon Steel _x000D_Collet Model and Specification: _x000D__x000D_Specification(Approx.)Upper Outer Diameter(Approx.)Lower Outer Diameter(Approx.)Inner Diameter(Approx.)Height(Approx.)Quantity_x000D_6mm / 0.2in11mm / 0.4in7mm / 0.28in6mm / 0.2in8.4mm / 0.33in1Pc_x000D_6.35mm / 0.25in11mm / 0.4in7mm / 0.28in6.35mm / 0.25in8.4mm / 0.33in1Pc_x000D_8mm / 0.31in11mm / 0.4in8.8mm / 0.35in8mm / 0.31in7mm / 0.28in1Pc_x000D_Nut Model and Specification: _x000D_SpecificationHeight(Approx.)Aperture(Approx.)Thread Aperture(Approx.)Quantity_x000D_For 6mm/6.35mm12mm / 0.5in7mm / 0.28in13mm / 0.5in2Pcs_x000D_For 8mm12mm / 0.5in8.5mm / 0.33in13mm / 0.5in1Pc 16Pcs in 1 Set: Comes with 3pcs router collet adapter and 3pcs screw in different sizes to satisfy your varied working needs. 2Carbon Steel: Adopting premium carbon steel material, all the adapters and screws have high strength and high hardness. 3Wide Application: Allows for wide application in the collet conversion on trimmer and engraving machine, practical to use. 4Good Workmanship: Having been through heat treatment and accuracy grinding, these adapters have excellent durability. 5Simple Carrying: Designed to have a light weight and a compact size, both the carrying and storage are very convenient. 3 x Router Collet Adapter 3 x Nut Please match the appropriate size before use.