Material: Clamp is made of zinc aluminum alloy for long life and high wear resistance. Dimensions: Workpiece holder is 50mm (L) x 20mm (W) x 56mm (H). DESIGN: The collet slot block size is designed for Genmitsu 3018 series CNC milling machines. It fits perfectly for CNC milling machines of the 3018 series. FEATURES: the gripper absorbs the material up to a thickness of less than 30 mm. It can accommodate most hardware for desktop CNC milling machines. VERSATILITY: This clamp provides a unique clamping effect for your universal T-slot system setups and assemblies. It is ideal for holding , position and fix workpieces in woodworking or metalworking, in conjunction with milling machines, drills, CNC milling or engraving machines, work benches, vertical milling machines and much more. Product Description Technical Details: Material: Zinc Aluminum Alloy. Dimensions: 50mm (L) x 20mm (W) x 56mm (H) (assembled). Package content: 4 T-slot clamps. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.