I bought this along with a Gunslick kit to make sure that all of my Carbon is fully functional. They easily fit in the gas tube, and it's not too hard running it through. My only problem is that they are maybe a little too flexible. About 3/4s down the gas tube it comes to a stop, and will only kink up if I try to shove it down further. But that's no problem. It might just be that my gas tube might have a slight crimp, but it also fits in at the receiver end, so I have either all or most of my tube free from corrosion.

These do their job, but really are unnecessary. There are thousands of pounds of pressure pushing through the gas tube, and that pressure will expell any carbon fouling in the gas system and you can just buy pipe cleaners from a craft store.

They are very long Pipe cleaners. They are the only way to clean the gas tube on my AR. There may be better pipe cleaners. But why? Use em once and discard them.

You're better off buying white pipe cleaners from a craft store.

One of the weak links in the design of the AR-15 / M-16 is the gas system. It gets dirty and starts to cause malfunctions. With these you will be able to clean your gas tube so that there are fewer malfunctions.