Children will have fun with this construction and early learning activity set. Ideal for developing fine motor skills and creative design. How many pebbles can you stack before they topple over? Encourage visual perception, sorting, counting, sequencing, stacking, and more. The wonderful tactile experience of the smooth, rubbery pebbles in six different colors will delight the senses. Set includes 48 plastic pebbles in 4 sizes and 6 colors, and 12 double-sided full-color activity cards. Pebbles measures largest 2-1/4″ x 1-1/4″ x 1/2″ to smallest 1″ x 1/2″ x 1/4″ .