Teflon® PFA is a perfluoroalkoxy copolymer resin. It can offer continuous service temperatures up to 260°C (500°F). Teflon® PFA provides superior creep resistance at high temperatures, excellent low-temperature toughness, and exceptional flame resistance. 
It also has a very low coefficient of friction compared to most other plastics. 

The listed price is per 100mm. 
If you want 600mm order quantity of 6 and it will be supplied in 1 length of 600mm. 
ID: 4mm OD: 6mm 
Ideal for use with 3mm diameter PLA and ABS filaments. 
This is slightly larger than the larger size shown in the photo with a piece of PLA from Diamondage sticking out of it.

This is suitable for use to guide filament into a direct feed type extruder for a Reprap machine or 3D printer.