Medium Length Wigs span from the bottom of the chin to the top of the shoulder or above the collarbone. Wigs with standard synthetic hair will come back to their Pre-Styled shape after washing. Wigs with heat-friendly synthetic hair can be styled up to 350°. For example Prong Iron Waves are a type of wavy hairstyle that is created using a Prong Iron. Prong Irons are designed with a unique barrel shape that creates deep, defined waves.