Material6061-T6 alloy hub-shell Axle14mm hollow bore, male axle, hardened heat-treated crmo Bearingsx3 high-quality bearing and bushing driver, x2 high-performance durable bearings in hub shell. Spokes36h   Driver9t, driver features x3 bearings for added support Features • revolutionary Freecoaster hub using the patented Wethepeople HYBRID SYSTEM internals. https://thehybridsystem.com• Freecoaster & Cassette in one hub• “MagnaDrive” Magnetic driver for increased performance & reliability• incredibly reliable and lightweight freecoaster hub mechanism• easily converts to a cassette hub with no additional parts• simple slack adjustment• durable and dependable 3-bearing system driver• available in RSD or LSD• includes Viper nylon hub guard and Gong driver hub guard Weight510g (17.9oz)