Thin Arms: 1.5mm Yamamoto high quality neoprene provides excellent flexibility. 3-4-4 design: Lifts the lower half of the body to improve body position, creating less drag and more speed while conserving energy. SCS coating which is hydrophobic. Silicone coated cuffs: A unique new feature for Blueseventy which improve durability and become very slick when wet allowing for easy removal. Worn a few times, slight wear on the knee. Please see pictures for more information.