Weight plates are flat, circular discs used in strength training and weightlifting. They come in various materials, such as rubber, metal, or a combination, and are designed to be added to barbells or dumbbells to increase resistance during exercises. Common weights include 2.5, 5, 10, 25, 35, and 45 pounds, allowing users to customize their workouts. These plates often have a central hole to fit onto the bar and may feature grips for easier handling. Olympic weight plates are standardized to fit Olympic barbells, which are typically 2 inches in diameter. Proper use of weight plates can enhance strength and muscle development.