This set encourages color and shape recognition. The bolts only fit with the nut having the same shape. Includes 4 types of illustrated plastic activity cards (16 total) which hold up great for classroom use. 36 of each nuts and bolts. The activities are based on: Recognizing colors, recognizing shapes, algorithms, recognizing colors and shapes. The activities have been tested in schools and highly rated by the teachers. This item also has a free digital component found on playminiland.com where you may find lesson plans and downloadable/printable activity cards. You may also access an online game that complements this toy.