A company called Protech seems to use thermoplastc for their outer boots. This makes them by far the best aftermarket choice for a CV axle.
As most of you know, almost every CV failure is because of torn boots, and it's always the outer boot/joint that fails due to the outer joint doing more movement. Most aftermarket axles, both new and poorly "rebuilt" "reman" axles, use cheap neoprene that only lasts a few years before it tears, and of course their "lifetime" warranty never covers torn boots
As most of you know, almost every CV failure is because of torn boots, and it's always the outer boot/joint that fails due to the outer joint doing more movement. Most aftermarket axles, both new and poorly "rebuilt" "reman" axles, use cheap neoprene that only lasts a few years before it tears, and of course their "lifetime" warranty never covers torn boots