The Rockin' Rectangle Pop-up is a fabulous generic pop-up die set. It makes great window cards, although of course you can use it without a window for a pop-up surprise inside the card. Opening the card will cause the rectangle to lift out and rock as the card opens and closes. These dies will work in different sized cards.  Set includes pop up mechanism die, 4 rectangle pieces, stitched oval and some small florets.  Instruction are included.  Embellishments shown here are not included.  Pick your theme and have fun making great interactive cards.  
Check out out Karen Burniston videos for inspiration and instructions.