Feature:1. This spring is very suitable for most extruder settings of 3D printers, great workmanship, perfect replacement for the old one.2. The spring has a long compression length, and the spring force can be fine‑tuned.3. Each spring can generate a compressive force of up to 1.6 kg, which is very elastic.4. A large number, can meet your use and replacement needs, very practically.5. With small size, easy to carry and store, convenient to use and with good performance.Specification:Item Type: Extruder Leveling SpringLength: Approx. 25mm / 1inLarge Head Size: Approx. 8mm / 0.3inSmall Head Size: Approx. 4mm / 0.2in Package List:20 x Spring