Building blocks make a great gift and help extend children's minds! Each set comes with 50 pieces in various colors including blue, yellow, red and green. Largest block measures 2 3/16" X 11/18" x 1/2" and on the top of the block, there are 12 little nubs with 6 across and 2 down. Smallest block is 11/18" X 3/8" X 1/2". Also includes tiny tires to make pieces move along with bodies to ride in cars. Comes packaged in a poly bag with header card. Not recommended for children under 3.