This caster set has the metal wheels. The wheels are the #3 size or only one-inch in diameter. Each wheel is fastened to a stout iron saddle, which is attached to a stem. The casters are designed to withstand a lot of weight.
Each stem has a nubbin at the top which will lock into a socket, if one is used. Sockets can be acquired elsewhere in the catalog. The stems are 1 1/2 inches long. The height of the caster from the base of the stem to the bottom of the wheel is 1 1/4 inches.
The set is a matched set and are in very good condition.