Inner Diameter of 60×8mm FS90R wheel

Does anyone know what the Inner Diameter of the rubber part of the 60x8mm FS90R wheel is? https://www.pololu.com/product/2819/specs

Hello.

It is not clear to me which dimension you are asking about. However, we have a dimensions diagram for the wheel that you can find under the “resources” tab on the product page. If the dimension you are looking for is not there, could you describe in more detail which dimension you are looking for? (If you could provide a diagram, that would be helpful). It might also be helpful to know what you are trying to do.

Grant