Overview: The function of PTFE is to reduce resistance and guide filament. The tube’s inner diameter is 2.5mm, and its outer diameter is 4mm. 
 
Compatibility: X1 Series Exclusive
 
In the Box:
PTFE Tube (3pcs ): 370mm*1, 550mm*2
 
Bambu PTFE Tube Technical Specifications:
Materials
PTFE
Package Weight
13g (3pcs)
Package Size
230*155*4 mm
Color
White translucency
 
Replacement: To learn more about replacing the PTFE Tubes: https://wiki.bambulab.com/en/x1/maintenance/replace-ptfe-tube