The icon is shaped like a square with a rounded top left corner and two pointed corners located at the top and bottom right. The bottom left corner curves off to form a long oval shapes that runs the whole bottom of the square but doesn't close on the right side.
This is a Return Book 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 13,100 icons, all in the same style and quality.