Features: 1.PC4 M6 FITTING: Bowden tube coupler thread M6/3mm, inner diameter 4mm, suitable for 4mm outer diameter tube. 2.PC4 01 FITTING: The thread is about 1/8, the upper part can be inserted into 4mm tube and self locking, the lower part thread is 1/8 teeth. 3.APPLICABLE MODELS: Pneumatic fittings for CR 10 10S S4 S5 , for CR10S Pro, for Ender 3, for Ender 3 Pro printers. 4.5 SETS: PC4 01 fitting is silver, PC4 M6 fitting is gold, five sets in total, sufficient quantity, please pay attention to distinguish. 5.METAL MATERIAL: Bowden tube coupler is made of metal, high hardness, more durable, easy to install, connected by male thread of quick coupling. specification:Item Type: 3D Printer Straight PC4 M6 Pneumatic Fitting Material: Metal Type: for PC4 M6 Pneumatic Coupling, for PC4 01 Quick Coupling Quantity: 5 Sets Applicable Models: for CR 10/10S, for S4 S5 CR 10S Pro, for Ender 3, for Ender 3 Pro Printers PackageList: 5 x PC4 M6 Pneumatic Fitting 5 x PC4 01 Pneumatic Fitting NoteThese 3D printer accessories are small parts. Please keep them away from children to avoid the danger of swallowing