I just googled square k card. Is this what you are looking for?
Square K card by Kay's Crafty Corner
If so it looks like a
swinging z-fold card, but with two more folds.
So instead of starting with one 4 1/4" x 8 1/2" piece of cardstock, start with a 3" x 12". Then score at 1 1/2", 3", 6" and 12".
If you want the card to be bigger, you will have to use two pieces of cardstock and adhere them together to get a longer strip.