Ball Rim Knob FurnitureBlack Antique rim knob. Round ball knob set for use with rim locks. This solid ball door knob can be a harmonious addition to a range of traditional homes. The shape allows it to be gripped easily, providing a solid and firm feel. A simple plain knob in its purest form. Comes with a 10 year mechanical guarantee. Suitable for domestic use. Ludlow Black Antique is a traditional range of furniture with a powder coated Black finish.