This icon consists of three horizontal bars, each one with a circular slider on it. The indication is this icon would take you to a menu which would allow you to change various options b adjusting sliders like this.
This is a Slider 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 13,700 icons, all in the same style and quality.