This is a Exit 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 12,500 icons, all in the same style and quality.
Consider a square with some part missing at the middle of the right side. There is an arrow pointing towards east or right side for which the tail starts from the center of square and head of arrow begins at the missing part on the right side of square.