Excellent die for creating window style cards, shakers, or peek a boos.  This will produce a stitched effect around the window and creates a stitched background border.  Full cuts on the three window panes and around the full window.  Hard to explain.  You should be able to get a close up when you hover the product photo.  
Die measures 9x9 cm (3.5 x 3.5 inches), and is compatible with standard die-cutting machines.