I want to get some UV film for my windows, obviously I'll keep my collection out of direct sunlight but it still gets very bright in there on a sunny day, so can't hurt. Can anyone recommend a supplier, or even some kind of certification? For example I found this, but how do I know it's not just cling film, it's not like I can ask for a refund in 10 years when everything is sun faded!
activewindowfilms.co.uk
Suggestions appreciated!

Museum UV Ultra Violet 99.5 Anti Fade UV Protection Window Film Clear
Museum Clear UV Ultra Violet 99.5 Anti-Fading UV Protection Window Film, Clear Heat Rejection Sticky Back Film, 50cm, 76cm, 100cm, 152cm, sold per metre.
Suggestions appreciated!