Nuts and Bolts Toys for Toddlers Preschoolers Kids STEM Educational Building Construction Screw Matching Activities

-- Build fine motor skills toy, improves memory, concentration, manual dexterity, hand-eye coordination, color recognition, pairing, shape sorting, increases attention and focus. -- Improve motion control, visual perception, cognitive thinking and problem-solving skills. -- Games for preschoolers, counting, sorting and kids matching game activities. -- Not every nut and bolt can match each other, breaking the traditional thinking. About 50PCS in total, 4 colors, 4 shapes and 4 sizes.