A weight plate is a weighted circular plate that is used in conjunction with barbells or adjustable ... dumbbells in order to increase the amount of resistance experienced by the user during weighted fitness exercises.The two main types of weight plates are "standard" plates, which are characterized by a one inch (25 mm) centre hole, and "Olympic" plates, which are characterized by a two-inch (50 mm) centre hole. Olympic plates are designed to fit the sleeves of Olympic barbells. Some Weight plates, such as radial plates, may provide two to three gaps in the plate for ease of carrying or to provide additional versatility to the plate. Non-competition plates usually have variable diameters and widths as opposed to competition plates which usually do not. Olympic plates can often come in the form of bumper plates. Bumper plates are usually made of a durable rubber. Bumper plates ensure that a loaded barbell can be dropped from a height during a bout of training and not cause damage to the surrounding floor, plates, and barbell.