One will find the porcelain casters (or rollers) on the older furniture, usually dating from the 1850s to 1900. These cast iron and porcelain wheels can stand a lot of weight and have been used for years as a lift for antique furniture and for ease in moving the piece around the house. This set has wheels that measure 1 5/8 inches round. The stem is 2 inches long. After inserting the stem into the leg, the height of the furniture will be raised about 2 inches.,Today, many people simply use the porcelain casters as an accent to the vintage item–to add authenticity to the antique.