These mounts are a much harder compound than oem/Powerflex etc. As such they do not deform and allow for very little movement, preventing the system from bouncing around as is common. As used by M Sports R2T Rally series. They also come with a fabric banding to further reduce unwanted flex and also act as a secondary measure in case the mount should fail on 1 of the extremely rough Rally stages.
ONLY USE SILICONE PASTE OR SILICONE LUBE WHEN FITTING. Any other type of lubricant will cause the hangers to perish.