This Rewind icon is a responsive icon. This means that it's optimized for four resolutions, from tiny 16x16 until highly detailed 80x80. The style comes from the latest Microsoft Office, which makes it perfect for any Windows applications, in particular, those with ribbon toolbar control. Unlike other icon packs that have merely hundreds of icons, this monster icon pack contains 15,500 icons, all in the same style and quality.
The icon is a rewind or back symbol. It consists of two triangles pointing to the left or backwards. Both triangles touch each other, with the second triangle having its apex obscured or abutted into the first triangle.