This is a Logout Rounded Up icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 13,000 icons, all in the same style and quality.
The image is of an incomplete circle. The top of the circle does not close. In the center of the circle is an arrow that is pointing straight up. The point of the arrow is where the opening of the circle is. The arrow does not touch the edge of the circle.