It's a logo of a rectangle with the longer side up as in portrait style. Inside the rectangle are zipper teeth starting from each upper corner and meeting in the middle of the image with a zipper as if something is being unzipped.
This Open Archive 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 16,000 icons, all in the same style and quality.