This Sign Out icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,400 icons, all in the same style and quality.
This icon is a very line line drawn in a circle with a small portion left blank on the right hand side. Inside of this empty portion is an arrow that is pointing towards the right. It starts in the center of the circle and ends right at its edge.