The picture below shows a larger view of this Ohio State University Advertising Souvenir Metal Swivel or Spinner KeyChain. This keychain is not dated and the year that it was made is unknown. It is not marked and the maker is also unknown. The keychain is made of brass and it has a screw type keyring connected to a chain, and an advertising fob or charm section. The center of the fob or charm spins or swivels around. Both sides are identical. It is marked on the two sides as follows:
OHIO STATE UNIVERSITY ® OHIO STATE ®
The keychain measures about 4-1/4'' long. It appears to be in near mint to mint condition as pictured.