Size Option Size Problem!!! Please choose size according to chestTag S for Chest 35.4-37"Tag M for Chest 37-40.1"Tag L for Chest 40.1-41.5"Tag XL for Chest 42.5-45.6"Tag XXL for Chest 45.6-48"Tag XXXL for Chest 48-51.2" Item details Neckline Detail Fashion simple design collar, generous. Reduce friction caused by riding. Using Self-locking Zipper Smooth non-card chain. It doesn't automatically open when you Cycling. Flexible Sleeve Flexible and unrestrained, the arm can freely stretch. Item details Elastic Side Large grid fabric in side. Highly Elastic,Highly Breathable. Skid Strip Hemlines with Skid Tape,Comfortable and prevent dislocation. High-quality non-slip tape, more comfortable Cycling experience. Pockets and Reflective Strips Pocket: Three pockets. Reflective Strips: Riding safely at night. Cycling Jersey Short Sleeve Cycling Jersey for cycling Make you feel more comfortable.