Moduł Netatmo w środku and other 85,000 icons from Icons8 icon pack follow the visual guidelines of the operating systems: Windows, iOS, Android KitKat, and Material. PNG format is free up to 100x100 px. Icons are availble for download in PNG and vector (SVG, PDF, EPS, and more).
It is an image that is composed of one larger vertical rectangle sitting on top of a smaller horizontal rectangle. The top rectangle has a vertical line drawn in center of the rectangle. The line is about half as tall as the rectangle. The bottom rectangle has a small vertical line drawn from the bottom center and extending halfway up.