Made from lightweight 7075-T6 aluminum with a natural finish, Specially designed for Mini/Micro Sprints fit 6-lug hubs with 5-1/4" bolt circle, Available from 35-55 tooth configurations to better suit your application, Will fit Speedway, Hyper, Stallard, RTS, PMP, Excell and other hubs, Has a .25" hole diameter and works with a 520 chain.