The set comes with 72 plastic connecting bars: 12 each in red (5.5"), blue (5"), yellow (4"), green (3.5"), purple (3"), and orange (2"). The flexible bars connect at either end (by simply popping them into place) and can rotate in conjunction with each other. Bars can also be attached to the center of the two included orange protractors. Includes 10 student sets (12 each of 6 different lengths that are color-coded), 1 transparent set (four each of 6 different lengths) and 24 activity cards stored in a reusable container. Grades K and up.