Back story. I had to get someone in to replace a broken side stay on our bathroom window. In talking about what to use to lubricate/protect the new fittings he recommended to use this in preference to WD-40. So, I bought a can and yes, IMHO it is much superior. The bathroom window still swings open at the slightest touch 4 months after treating and daily use. And the plus side is that it does not contain silcone or CFCs.
As it's classed as a professional product it's not available from the usual suspects. I got mine from All Fix but the AC website says there are over 400 UK distributors plus others worldwide.