Block Mates build upon the wonderful foundation of unit blocks by providing children with a themed exploration set, enhancing the original principles of block-building. They are engineered to fit standard unit blocks and can be built in their natural form or mixed and matched with others in the set to create new, imaginative creatures. The patented gasket design ensures a snug fit. This set of Farm Animals include Goat, Sheep, Pig, Cow and Horse. Features patented nylon gasket. Blocks not included. Ages 3+.(Blocks not included). For the perfect block fit see our item # GD7600.