Features: Made from Durable brass with Excellent Rust/Oxidation resistance, keeping long term use. Each 3D printed nut with thread insert in this product has been carefully polish and has no burrs on surface. 3D printed nut has twills thread, and the high-precisions internal thread ensure that the nut fit tightly to the installation object and creates a certain friction and bites force that can be fixed to the installation object. Prevent falls. These Threaded Inserts were packed in a reinforced case with Dividers and Latches. Package Content: You will get 300Pcs 2/2.5/3/4/5/6mm 3D Printing Brass Nuts Inserts with different lengths. Specifications: Material: brass Size: As Shown in the Picture Package Includes: 300Pcs 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 the difference between different monitors, the picture may not reflect the actual color of the item.