Features: Make from brass with Excellent Rusts/Oxidation resistance, keep long terms use. Each 3D printed nut with thread insert in this product have been carefully polishes and have no burrs on surfaces. 3D printed nut have twills thread, and the high-precisions internal thread ensures that the nut fit tightly to the installation object and creates a certain frictions and bites force that can be fixed to the installation object. Prevent fall. These Threaded Inserts were packed in a reinforced case with Dividers and Latches. Package Content: You will get 380Pcs 3D Printing Brass Nut Inserts with different lengths. Specifications: Materials: Brass Size: As Shown in the Picture Package Includes: 380Pcs Metric Threaded Inserts note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.