Build a simple shape or a 3-D flying object with the 400-piece Criss-Cross Connectors Set that includes triangles, circles, squares and pentagons. Learn basic geometry by identifying shapes by the number of corners. Graduate to spatial thinking and pattern recognition by piecing the units together to create a geometric pattern or object. Shapes come in five colors: blue, green, yellow, red and orange for use by children 3 and up. To clean, wash pieces in the sink with a clean sponge or rage, soap and warm water.