This is a New York Yankees Collectible Pin. It is a replica of a World Series Pin. It has the logo of that years Series with each team logo on a side. This may not be an exact replica of the World Series Pin. They may have added the logos for effect. 

It measures about 1.5 by 1.5  inches.

This is made from the mid 2000's. These came from a 2 pack. As far as I know you had to buy the whole set and not each individually.