Brooks Men's Summon 3 Running Shoe 100% mesh Rubber sole Hydroflow - Dynamic fluid units for heel and forefoot enhance midsole cushioning, shock da BioS-257 - When the material enters a landfill, a non-toxic natural additive within the Bi DRB ACCEL - Thermoplastic device provides torsional rigidity to midfoot, enhancing suppor HPR PLUS - A higher durability, abrasion-resistant rubber outsole compound that wears long Engineered Hyper Pod Configuration - Midsole and outsole components are engineered to set