I've had am pro knee pads for years now. Practically made for life, all you need to do is de stone this front occasionally. The only problem I have with them is the straps, they're for quite chunky legs and mine ain't. I've actually removed mine and replaced with old canvas belts which work perfectly. I have just urged two other tilers(with suffering knees) to get a pair. They are having the same problem. I know there is 2 Velcro patches to stick to but I can't for the life of me work out how to use the second patch. I once saw some parquet guys who'd solved it but I can't remember. Anyone know the answer?