The Nike LunarSpider R3 racing flat gives speed with comfort. Super light single-layer mono diva mesh upper provides added breathability. Flywire technology secures the support on midfoot area. Lunarlon cushioning system features a Lunar foam core that delivers ultra-plush cushioning and a springy response. Strategically placed segments of BRS 1000 carbon rubber, Duralon and DSP offers runners the durability, cushioning and grip for racing and training. Wt. 5.8 oz.