[15 different sizes to meet your needs. different requirements] The knurled nut; brass barrel contains 330 knurled nuts and a total of 15 different sizes of threaded inserts: M2: 4x3.5mm, M4: 4x6mm, M2: 6x3.5mm, M4 ;: 6x6mm, M2: 8x3.5mm, M4: 8x6mm, M2: 10x3.5mm, M4: 10x6mm, M3: 4x5mm, M5: 6x7mm, M3: 6x5mm , M5: 8x7mm, M3: 8x5mm, M5: 50x7mm, M5: 10x7mm Your different needs. [Stable and durable] - The insert nut is made of ; made of high quality brass, which exhibits the characteristics of hardness. high, resistance to wear, resistance to oxidation, resistance to corrosion, resistance to corrosion, resistance to heat, long life, high pressure and Christmasdeformation, and stable integration. [Easy to install. use] Énuts high performance pressure, threaded inserts are self-locking nuts. pressure developed for later insertion into 3D printer parts, such as Creality, Anycubic or Prusa printers. The nut with spring can be easily integrated; into the blind hole or through hole by ultrasonic