[ Threaded Inserts Assortment]: Knurled nuts with internal threads are made of brass, which has the optimal thermal conductivity and resistance, ensuring that each nut inserts last for a long time. [Multiple Standard Sizes]: In this kit, you get 350pcs M2 M2.5 M3 M5 M6 female knurled nuts in different lengths, total 18 sizes. Super large quantity and sizes can meet your needs to install numerous 3D printing accessories. [Firm Hold and Easy to Use]: The brass threaded insert can be installed into the part of the 3d printer by heating or ultrasonic. Due to the geometry of the threaded sleeve, it holds firmly in the pressure part. The opposing spiral knurled nut ensures a high balance of tightening and loosening torque. Through the guide, insertion has been greatly simplified. [Thickened Storage Case]: This threaded inserts assortment kit comes with a reinforced case, with thickened dividers and latches, keeping all brass nuts well organized, clear labels pasted on the inner and outer lids, easy to store and at hand when needed. [Wide Applications]: These heat set insert are suitable for plastics and can be inserted in tapered holes by heating or ultrasonic, as well as by molding. Colour:Yellow Material:brass Package Contents: 350 x Thread Knurled Nuts 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.