CT-105 is a platform caster with a porcelain wheel with a serrated stem. The stem and fork are both made of cast brass. This item does not require a socket as it attached with three matching screws (provided) through holes found in the bottom of the platform. The wheel is 1" in diameter by 1/2" wide. The stem is 1" long by 1/4" in diameter. The platform is 1 1/8" in diameter. Furniture is elevated by 1 3/8" when in stalled. Matching installation hardware is included.