Five different farm animals each with 4 pieces. Block Mates will revolutionize the way kids play with unit/project blocks. Slide the Block Mates onto a standard-sized (13cm x 3cm) unit block to create fun play friends. Heavy duty plastic parts with a nylon fitting ensures a snug fit over existing blocks. Mix and match the parts to create lots of very different and fun animals. The vehicles have rugged wheels and steel axles.