Expensive to fit compared to others available. installed 2020 with 5 yr warranty. Recently started to stick when opening or closing, making loud banging and clattering noise. Very shortly after, door unrolled itself and jammed in the top of the door frame. managed to unjam it from the frame and free it off. Reported it as a warranty issue to crocodile. Engineer called and examined the door. operated it a couple of times up and down . still clattering. Said he could not find anything wrong, but to lubricate it with wd40. Works now after a fasion but still sticking. not brilliant result. Still have 3 years warranty. They may well be back!