Thank you everyone for your input and advice. The current ones we are using are rather old but I believe we got them from andymark and are 6" diameter. They do not sell them any more but they look like the image that I linked below. The only difference is that the rollers were a light brown color. The Durometer of the rollers seemed pretty low. Thanks again for everyone's help. We do not want to have to worry about marking up floors when driving around our school or if we are at a PR event
