Suitable for 3D printing: Brass threaded inserts, which can be embedded into plastic materials using the heat from a soldering iron or ultrasound, are the optimal solution for adding threads in 3D printing. Common specifications: We have created this set of inserts using a large quantity of M3 inserts combined with M4 and M5 inserts, based on the most commonly used specifications by 3D printing enthusiasts. The heights range from 3mm to 12mm. We hope you will like it. Secure fixation: Our brass threaded inserts are made of high-quality brass and undergo precision processing, ensuring excellent heat conduction and corrosion resistance. Through testing, we have found that compared to straight-threaded inserts, the knurled threaded inserts provide stronger gripping strength and can withstand high levels of tensile force. Clear labeling: Each specification has its own independent compartment in the plastic box, and we have attached labels with detailed annotations for key data, making it convenient to use. Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you!Plastic box randomized , don't accept the specified! Colour:gold Material:brass Package Contents: 420 x Threaded Inserts Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.