Can this be used outside?

Maybe if placed in a dry area out of rain. I believe it is rated down to 32F. I deployed one outside in central North Carolina and it works reliably at considerably lower temperatures.

You probably could get away with it, but I think moisture would eventually kill it. No rubber gaskets around the batter cover that would give any indication it was meant for a wet area. Just not sure if it would last 1 month, 1 year or 10 years. For the price, I would say try one and see how it fares.

Yes, this can be used outside.