The heads of the cast metal dumbbells are encased in thick rubber to prevent damage to the weights, floors and other equipment in the exercise facility. Octagonal head design keeps them from rolling away. Ergonomic, knurled handles provide a comfortable, stable grip. Durable construction that is ideal in frequent-use settings. Twenty-seven weights available, from 3 to 100 lbs. Sold individually. Racks available. 2-year limited warranty.