Comes in a set (TWO foams included)

RC car "foam" inserts can be made soft or firm
Soft tire inserts: For RC cars 5-6 lbs
Firm tire inserts: For RC cars >6 lbs
Designed to fit a 4.75" tall tire and 1.9" wheel

Will fit most popular brand tire including Proline, JConcepts, Vanquish, and Pitbull tires