Faster than the Ninja ABEC 3's because some skaters just want more. Ultra-low friction machined nylon retainers, super hardened and ground to perfection AKS balls, super honed and polished raceways using superior high carbon steel (SUJ2), full contact metal shield on one side for easy serviceability, with labyrinth inner and outer ring geometry to resist contamination. USO = Ultra Speed Oil; a super lightweight synthetic speed oil that resists thermal breakdown, resists spin-out and will not attract contaminants… micro-filtered. NiNjA 5s are designed specifically for excellent skating performance, every day, and EXIT real world's got them here for you