PicassoTiles 100 piece Fortress Construction Building Kit (SKU: PTC100) is easy to build and durable with the updated latch clicking system. It comes with 34 colorful geometric interlocking joints in four colors, 56 connecting sticks with new locking mechanism on the two ends to secure the fort buildings, and 10 extended cross tubes to improve the stabilities. Each joint is designed with 18 snapping holes in different directions to allow kids to engineer forts in all fun shapes, structures and sizes.