|Van Drop Box|
These come off a Lego Technic set with number 8479, the green scanner truck for those who are familiar with Lego (who isn't :)). You can buy the tires separatly and they also have the rims. You can look for a shop closer using the product numbers on this website.
The servo horn I used ships with the 9g servo's. They fit exactly inside this wheel. I used some tie wraps to keep it in place.
Now I'll be looking for some platform to attach these wheels to.