Today, virtually all cables use some kind of polymer for insulation purposes because it is very cheap and there is a general belief, that as long as the dielectric constant is low, everything is fine. Of course, there is some truth to this - but just some - since air does sound better than Teflon and Teflon does sound better than PVC.

RVM - short for Reduce Vibration Material - is the BrainPower answer to address two well known yet insufficently covered problems in cable design.

100% music with the right tonalbalans
live stage with focus and 3D
crispy, correct timbre and slam