the model 2076 dolly is a cast iron base 10in end to end with 1-1/4in deep center hole, measuring 1-3/4in at the top and 1-1/4in at the bottom. overall height is 4-1/4in. The 2-1/2in diameter wheels are chosen based on the weight carried and the environmental needs. The high grade hard rubber tread wheels are used for providing maximum floor protection; made from natural hard rubber 95 shore a rubber with self-lubricating bushed bore. This wheel provides a weight capacity of 525 lbs. Per dolly. Each dolly weighs 14.5 lbs.