Tennis shoes K-SWISS DEFIER RS. A K-Swiss classic updated for today . Hight playability combies with traditional styling for today's competitive player. The shoes are from performance serie designed for playing on a clay surface, and hardcourt surfaces.Technology used:Heel Grip Lining - A special lining reduces foot-skiing inside the shoeStay-Tied laces - strengthened shoe laces that help to tighten the shoe, reduce foot movement in itShock spring - special pads that increase amortizationAosta 70 - a high-density rubber sole that gives unrivaled durabilityOrtholite - antimicrobial, moisture regulator, which helps to remove sweat odorDragGuard - strengthening material in the heel and fingers, which reduces the wear of the pad