Two specially die cut diagonal pieces that are pre-scored into 3 panels and pre-cut with a slit in each panel. The 2 halves have the slits opposite on each panel, so they interlock together.
OR think outside the box and if you don't want to make an interlocking Cascading Card...just decorate one side for a Diagonal Tri-Fold Card
Folded Card Size is 4.25 x 5.5
Kit includes 5 each of: Die Cut Cards (2 sides, so a total of 10 Diagonal pieces) & A-6 envelopes