Did you recently ask this question? ANyway, Uphonor (originally Wirsbo) is essentially the originator of the material, been at it the longest, and one of the few that make it using process labeled type -A, which is the most flexible (can bend it into the smallest radius of the types minimizing the need for fittings), supports the expansion system which has the fewest flow restrictions, and is the only type that can be repaired if you kink it without cutting out the kink and installing a fitting.