Tecnica Men's Spider X Lite MS Trail Running Shoe 100% Synthetic, Textile Imported Rubber sole TRS-Tecnica Rolling System provides better shock absorption on a wider bottom platform with a longer and smoother rolling transistion and ending with a more efficent propulsion for the runner T-Spot provides super absorbing heel material and shape provides optimum comfort and energy from heel strike and initiates rolling process Lateral Catamaran is our low profile cradle integrated with outsole material to provide maximum dynamic lateral support Stab Heel provide laterial stability using composite external "wings" thus locking the heel in place TecniGrip is our premium rubber composite outsole combined with the rolling spine and rolling profile provides maximum grip by ensuring maximum surface area in ground contact