These round plastic pipe plugs are a durable solution for many home or outdoor furniture, including metal tubes, bunk bed ladders, tubular metal legs, prefabricated cushioning, dining room chairs, chair legs, barstools, kitchen chairs, hollow chair legs, or any round opening Alternatives. Made of good quality plastic, these round caps are strong, durable, shockproof, waterproof, abrasion-resistant, and designed to withstand impact. Black plastic plugs prevent scuffing on wood or other types of floors. They provide a protective “glide” for chair tips, bench legs, table legs, bar stools, and patio furniture.