The upper section of the suit, the body jacket, is perforated all over to allow a much better flow of air through the clothing. The benefit of this is that your body stays cooler. There are two ways to wear the body jacket. You can zip the pants and body jacket together or you can tuck the flap of your jacket into the pants with your jersey. Not using the zip increases your freedom of movement on the bike. - made using 80% neat leather for the best upper body protection - leather thickness between 1.4 and 1.6mm - extra protection from elbow and shoulder protectors - strong but comfortable back protector with kidney belt - double-stitched seams - extra protection from thicker material on the chest - more freedom of movement with elasticated armpits