This Low Volume icon is made in Material Design style developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 4,400 icons, all in the same style and quality.
The icon looks like a triangle with curved edges laying vertical but the point facing left is missing. It is replaced with a smaller rectangle shape with curved edges. At the base of the vertical triangle which is facing left is a small backwards C shape at the center.