Product review (5 stars): Solved my problem.
I had a perfectly good copper water line I ran when we bought our new fridge but over time it developed a very annoying rattle/buzz.  I replaced it with this poly line and it completely solved my problem.  It was very frustrating having a noisy 3K refrigerator but now it is silent.  Probably the first time in my life doing something the "best" way was actually causing the problem.