The Non-Drive side of the Optimized freecoaster was designed completely around grinding - Included is a completely integrated non-drive side plastic hub guard that easily slides over the existing cone to simpifly your installation experience The Non-Drive side of the Optimized freecoaster was designed completely around grinding - Included is a completely integrated non-drive side plastic hub guard that easily slides over the existing cone to simpifly your installation experience Redesigned and improved internal bushing resistance system for improved engagement CNC 6061 alloy hub shell 14mm solid cro-mo male axle 9T 1pc CNC cro-mo driver Proprietary plastic non-drive side hub guard 2 fsealed cartridge driver bearings, 2 sealed cartridge hub shell bearings