This is a pair of two AKA Racing Closed Cell Inserts, and are intended for use with 1/10 Scale 2WD Stadium Trucks. AKA, the pioneer of the closed cell insert, has created these inserts for use in the front or rear tires of your 1/10 scale 2WD truck.
These inserts were designed to decrease the lateral deflection of the tire while at the same time increase the vertical impact absorption. This providing better handling in the bumps and greater stability. Using a softer foam or hollowing out the inner circumference like other companies do still leaves the car feeling squirmy with a less accurate feeling through the bumps - not to mention the loss of durability. Gil Losi and Mark Pavidis knew this compromise was not the solution. The solution they found was the addition of lateral grooves to the inner diameter. The lateral grooves allow the insert to flex vertically to absorb the large impacts while still maintaining lateral stability and overall durability AKA inserts are known for. No compromises. The result is a more predictable handling truck without giving up durability.