Monoballs deliver precise, razor sharp handling. but rapid wear has made them impractical for all but the most serious racers. Not anymore! Weather seals - our proprietary-design monoball cartridges have weather seals to keep dirt out and extend product life. this is the only monoball suitable for street or extended track use. dirt and water contaminate ordinary products and accelerate wear. Performance - today s sticky tire compounds generate corner loads that easily compress factory rubber bushings causing wandering alignment settings. Camber and toe flop around upredictably. weather-sealed monoball cartridges replace compliant factory rubber bushings with hardened-steel spherical bearings. Unlike poly bushings that bind and resist movement, true spherical bearings allow free motion on multiple axis. Sold as a pair.