This set includes four 1-1/2 inch flipper rings made of factory original rubber. They are designed to meet or exceed factory specifications and are used in 99% of all full size arcade pinball machines. These flipper rings are direct replacements for use in various arcade pinball machines, including Stern, Williams, Bally, Jersey Jack, Spooky, Barrel Of Fun, Gottlieb, and Multimorphic models. They are compatible with 3 inch flipper bats and are not suitable for toy or home pinball machines with smaller diameter balls.