Rubber soleTHIS SHOE IS FOR: Runners who want pure luxury right at their feet. Super-soft cushioning, innovative support and a plush fit add up to maximum comfort. This is Brooks most cushioned shoe for feet that are looking for support!PLUSH FIT: The plush interior liner surrounds your foot and moves and expands with your unique running stride. The engineered mesh upper and 3D Fit Print technology only enhance the fit.FOOT SUPPORT: Ideal for runners looking for support. Our Guiderail Support System focuses beyond the feet to the most injury-prone part of a runner??s body: the knees. GuideRails keep you moving comfortably by keeping excess movement in check.SUPER-SOFT CUSHIONING: The reconfigured midsole and outsole ratio allows an increase in DNA LOFT for even more extreme softness underfoot without losing responsiveness or durability on your run. An OrthoLite sockliner provides premium step-in comfort.SECURE FIT: The 3D Fit Print saddle applies strategic stretch and structure for an impeccably secure fit.