Rearfoot GEL provides cushioning in all directions absorbs impact forces and helps to stabilise the foot during heel contact. Forefoot GEL reduces the loading forces as the foot moves into propulsion, improving performance and minimising the risk of injury. The Trusstic system is employed to reduce the weight of the sole unit while retaining the structural integrity of the shoe so you get excellent support combined with lightweight durability. AHAR + stands for Asics High Abrasion Rubber which has been placed in critical areas of the outsole for exceptional durability. The NC Rubber Outsole contains more natural rubber content than traditional solid rubber, which results in enhanced traction on court systems. This outsole is also non-marking and won't leave any marks on indoor courts.