This here box-like device that is attached like a symbiote to our roof is a solar-powered attic vent. When the sun is shining, and thus cooking the roof, it fires up and a blower fan helps remove hot air from the attic, thus helping to cool the house. Fully self-contained, and simple yet elegant and seems to really help when you need it most, i.e. hot, sunny summer days. It’s not cheap, but is basically a zero-maintenance device. If you live in the sun belt, I’d buy two.