Is this a reliable vent? Will it open at the correct temp, and close tightly when its cold? Will this install on a homemade greenhouse, or does it have to be used on a Solexx greenhouse?

I need an intake vent that opens and closes based on temperature, and I like the idea of not using any more electricity to do it.

Any other products you might recommend? I don't mind one that needs electricity, but only if pulls low amps...