The X? stands for xtreme in this xaggerated reboot of PUMA's 1980s Running System sneaker that pushes the boundaries of proportion, texture, shape and comfort. It's deconstructed and rebuilt with layers of color-block suede and synthetics over breathable mesh that keep the look endlessly interesting and easily versatile. Style Name: Puma Rs-X? Layers Sneaker (Women). Style Number: 6086358.