CFD-based fabric placement and seam construction Engineered for aero efficiency at 30 to 55 km/h Airflow shoulder construction Velocity Rev2 fabric on front and sleeve 3D mesh back for breathability Elbow-length stretch sleeves with raw-cut edge YKK® Vislon® zipper Drop tail allows perfect pocket placement while keeping jersey fitting well at waist The integrated transparent number pocket on the back removes the need to pin on race numbers and improves the aerodynamics around the lower back Weight:119 g