These are an extra set of tires that fit the replacement idler wheels that I have listed separately. Should you ever need to replace the tires that came on your idler for any reason, these can be installed easily to make your idler like-new again. You can also keep a set as spares for any future need.
Used in models sold by RCA and other companies using the RP168 and RP190 changer mechanism that used the 74007 idler wheel. These include models like the 45J2, 45EY2, 45EY3, etc.
Note that these ship in a small padded envelope with a stamp.