Sidi t 4 air carbon composite shoes sidi t 4 air carbon composite shoes triathlon specific design for maximum drainage and ventilationthe upper has a plush brushed interior with minimal seams for sock free comfort and is now vented for air flow and water drainagethe large heel loop and notched straps allow for quick transitionsfeaturing sidis twelve carbon composite sole a mechanically stable material that is completely non absorbent to waterthe reinforced heel will keep the foot in place