The Nike Swift Cap contours to the head due to its multiple tension zones and overall three-demensional design. The opening of the cap uses a firm silicone compound to produce a tight seal. The caps' midsection is soft and pliable to allow a comfortable fit around the ears. To help decrease drag and create a wrinkle free surface, the crown of the Nike Swift Cap uses a rigid silicone to mold to the head. All this is achieved while paying particular attention to reduce weight and provide a superior fit.