PTFE Teflon tubing 25ft - 3mm ID X 4mm OD - Allen Tech PTFE Teflon tube

I bought this to use as a reverse Bowden on my 3d printer and it works great. I chose the 4mm OD 3mm ID so there would be less restriction in the feed to the direct drive extruder. I haven't tested it with flexible filament like TPU but I imagine it won't give me any issues.

I use my printers primarily for business, so when they are down I’m losing money. The ID is a bit larger than the BL OEM tubes but these had next day delivery so I went with them. This tubing has worked without any issues. Good value for the money. Would buy again when needed.

This is good to run between a spool (or filament dryer, like I did) and an extruder, as it's very loose and won't add appreciable drag while your extruder is pulling the filament. Because it's less draggy, it's better for this purpose than what you'd place between an extruder and hot end.However, it's useless for a "regular" Bowden setup (between extruder and hot end.) The ID (inside diameter) is too wide, allowing the filament too much freedom to move around at random angles, effectively changing the amount of pressure according to where the nozzle is, and that's no good. I tried that and found that it lead to weird inconsistencies in finish, especially at the top layer. So, for a regular bowden setup, use something with a slightly narrower ID.

Running on a Bambu Lab P1 Series.It's pretty much more see-through than other PTFE white tubes, very useful when loading/unloading.I use it with normal 1.75mm filament, absolutely 0 drag its very slick.Wouldn't suggest to print TPU with this as its not tight fitting, for the diameter mentioned above, but for pretty much anything else its a dream for printers extruder parts. No stress on components when pulling at all.HOWEVER, it is very easy to kink/bend.. if you try. But if accidentally create a bend they give you so much ft just cut and use more.Thermally is ok, I print ASA and chamber temps get 120F inside, and the filament in tube does not feel that heat so it is stiff while it runs through as should be.4/5 starts - (due to tube not being as stiff, not a serious issue at all, but can't say it's perfect)

Used it for draining a dehumidifier and it works perfectly

Good size for fitting into 3d printers compression fittings. And used it on a sunlu filament dryer.

the 3mm id is perfect for 1.75mm filament. Gives you a lot more slack resulting in less wear and tare on your extruder

Tubing is as advertised. Make sure to opt for Amazon packaging.I ordered two rolls. One was fine, the other was completely flattened rendering it useless.

No problems, working well.