Hydrogen Blue Sapphire Hyper Pink Epic React Flyknit 2 running shoe that combines Nike's innovative React cushioning technology with a lightweight and breathable Flyknit upper. The shoe has an interesting colorway featuring Hydrogen Blue as the predominant color, with accents of pink, lime and a darker shade of blue all throughout. It has Nike's React foam midsole for cushioning and impact absorption, while the outsole is made from rubber. Slightly worn, see images for imperfections.