Solar powered vent. There is a small fan in there I do believe.

Yup, here it is in Amazon,

Ultra-Fab Products 53-945001 Mini Solar Plumbing Vent

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https://www.amazon.com/Ultra-Fab-53-945001-Solar-Plumbing-White/dp/B004UQV3II/ref=sr\_1\_3?crid=39ANYA5QRSSDJ&keywords=solar+powered+rv+vent&qid=1665493948&qu=eyJxc2MiOiIzLjA2IiwicXNhIjoiMi4xNiIsInFzcCI6IjAuMDAifQ%3D%3D&sprefix=solar+powered+rv+vent%2Caps%2C104&sr=8-3