Compatible with BBL's Upgraded Pneumatic PTFE Tubing Connector for Longer Service Compared to Original The Tube Fitting is the assembly that connects the PTFE tubing, which is mounted on the back of the printer and is used to connect the PTFE tubing between the buffer and the tool head Comes with a storage case and you have the option to glue the connector to the back of the 3D printer Made of stainless steel, prevent oxidation, heat-resistant, not easy to deform 3PCS BBL Upgrade PTFE Tube Connector Compatible with X1 X1C X1E P1P P1S