This icon is a small circle with another circle behind it. The first circle has the number "1" in the center of it. You cannot see the circle behind the first circle. It looks like it could be a 3D cylinder.
This is the Average icon for
Windows 10. Here we go. Optimized for 32x32 px, these are the simplest icons in the line style. Downloadable formats are PNG and SVG, among others. Icons8 icon pack is unique in providing a huge number of icons designed by the same team of four designers who create the new icons every working day in the same style and with the same quality. Same cool as the Bat Face, huh.