These small one-inch steel wheels all match. The stems are slightly different because of past use and alterations. They are from 1 3/8 to 1 5/8 inches in length. The construction of the casters also allow the caster to rotate on the stem for a 360 degree radius. These casters were meant to be pounded into the wooden leg. The lift to the piece of furniture after inserting the casters is about 1 1/2 inches. This set is quite old, dating before 1900.