The TNT Rapid Fire Pro Cassette Hubs are designed after the original Derringer & Revolver models. They feature a unique body style that is CNC machined from 6061-T6 aluminum with 3/8" solid chromoly female axles in order to provide a high quality construction that matches up to their performance. Features: CNC machined 6061-T6 aluminum hub body 3/8" solid chromoly female axles Machined aluminum hardware Precision sealed bearings Shimano compatible chromoly driver w/ 3 pawl engagement Includes 16T chromoly cog, spacers, and lockring Specifications: Spokes: (36H) Front Hub Axle: 3/8" Female Rear Hub Axle: 3/8" Female Driver: 16T Chromoly Front Hub Weight: 9.6 oz / 272 g Rear Hub Weight: 16.9 oz / 478 g Dan's Comp offers a variety of Hub Accessories to fit most BMX hubs.