No official measurements here but though I'd prefer not to use it, and I haven't put it back up yet this year, I can feel the difference on my bald head. Call it what you want but if it helps that's good enough for me. I'm not that vested in a $75 shade.With complete respect, could this be confirmation bias? I ask because I am in a hot southern state (purchased June last year) and cannot feel any radiated hear from the roof but in fairness I do not have the cover nor have I measured...
On that note, I got it early on before they came up with the magnets - they sent them to me but I won't stick them on. Hopefully someone will develop a better solution.