Nail-in furniture glides
are recommended where casters are not desired. They facilitate the moving of chairs and other furnishings over a specific type of flooring.
Use nickel-plated steel glides on a carpeted floor. Felt glides are used on wood, tile, and laminate floors. Where more than one floor covering may be a possibility, plastic glides are recommended.
Single prong glides are used on legs of smaller diameters. Use 3-prong glides when your furniture leg is 1" in diameter or greater.Here's some information about glides.