Pneumatic PTFE Tube PC4-M10 Connector Parts for Bowden Extruder 3D Printer, Black PC4-M10 is easy to connect by inserting the tube and it will lock automatically Easily disconnect the tube by exerting pressure on the black cap. The elliptical sleeve allows you to easily apply and remove the tube in tight spaces. The PC4-M10 straight pneumatic connectors is widely compatible with Extruder, Hotend and PTFE Tube.