Set of 16 non-slip rubber tips for table and tubular legs. 19 or 20mm - Black - The size refers to the outside diameter of the tube to which the ferrule is to be mounted. A ruler may be more accurate than a tape measure for measuring. If unsure about measurements, please order a measuring guide with appropriately sized cutouts to place against the leg - this will indicate the size you need. Durable: with thick rubber sides and an internal reinforcing ridge. Ideal for replacing the rubber tips on chairs, tables, ladders, ironing boards, and other furniture legs, renewing your old, worn items, reducing noise, and protecting your floors.