1、Made of high quality stainless steel, strong and durable, has a long service life. 2、This product has the characteristics of anti‑oxidation and anti‑rust, and can be used in harsh environments. 3、This connector is a good accessory for 3D printer extruder with high performance. 4、The connector has great workmanship, can perfect replacement for the old one. 5、Small size, easy to carry and store, convenient to use and with good performance. 12 x Pneumatic Fitting Push Connector12 x Accessories Pneumatic Fitting Push ConnectorPTFE Tube Outer Diameter: Approx. 4mm / 0.16inThread: Approx. 6mm / 0.24inThe upper part (black) can be inserted into 4mm PTFE tube and self-lockingProduct Introduction: High-quality accessories, suitable for this application. Effectively prevent the occurrence of paper jams!Features: It Is Widely Used To Connect Bowden Extruders. It Can be easily connected by inserting a tube, and it will automatically lock. Simply press the black cap PC4-M10 to easily disconnect the tube: The upper part can be inserted into a tube with a diameter of 4MM and self-locking, the following threads are M10 and 1 point (about 9.6MM)Size:Approx. 9.6mm / 0.4in