This was the reply from the company, all sounds promising.
They are over size, so you just fit and cut back for clean fit. They have internal metal grippers so grip nice and tight, if you not pulling them off should last for years. Colour depends on sunlight I have had the red supplied to a lady from Spain and 2yrs down the line it had gone a lighter pink colour rather than red, but UK should be fine.
We are already quite well known to the Eriba owners as it was through them at the start we got involved with all this after sending various samples they settled on these trims, we supplied a batch FOC for the meet up in Wales a few years ago that were raffled off to raise money for charity.
They have sold very well over the years, only problems we really get is the occasional person who thinks it should be a seal rather than a trim! Otherwise its a nice simple trim that works well and for a change is not made in the far east!