This is a Left Click Filled 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 12,400 icons, all in the same style and quality.
It's a computer mouse. The clicker on the left side of the mouse has been shaded with dots, and extending from the direction of the left clicker are two waves. The waves get bigger the further they go outward.