Product Name: Knurled Nuts Assortment Kit Material: Brass Size: M2 M2.5 M3 M4 M5 M6, 1/4-20 x 12.7 x 8 Made of durable brass. High strength without deformation, abrasion and corrosion resistance and with beautiful and practical. Smooth surface with no burr, standard circular, firm and uniform, easy to install. Super large quantity and various sizes can meet your needs to install numerous 3D printing accessories. You can use a soldering iron to heat it up and then pressing it into the hole. It is easy to control and at a low cost. Suitable for various plastics and can be inserted in tapered holes by heating or ultrasonic, as well as by injection molding. Package Included: 1 x Knurled Nuts Assortment Kit Note: 1.Please allow a little size error due to manual measurement. 2.The colors may exist slight difference due to different screens. 3.If you have any questions, please feel free to contact us, we will solve it for you within 24 hours.