Brooks Men's Ravenna 2 Running Shoe Rubber sole Extra Adjusability in the upper reacts to tired swollen feet to give you the best possible Hydroflow - fluid-filled centre chamber reduces the shock at impact and take off and dynam BIOMOGO - Brooks introduces the first-ever biodegradable running shoe midsole DRB (Diagonal Rollbar) - dual density post is biomechanically engineered to allow for prog Sprung Lasted forefoot for increased propulsion