This is a Details 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 12,900 icons, all in the same style and quality.
There are three squares that are lined up vertically and they have two dashes beside each one. The first square contains a mountain and sun. The second square has a five petal flower inside. The third and bottom square has a sun inside.