Toratani "Good Circulation Shirt" The biggest feature is that the sleeves are attached facing the back, constantly pulling the arms back. In any posture, the force of bringing the shoulder blades together (closing) continues to work, allowing you to maintain a posture similar to the penguin pose. In daily life, the force that constantly pulls the shoulder blades together, which tend to spread when working with your arms in front of you, is at work. By repeatedly opening and closing the shoulder blades according to the movement of the body, you stretch the shoulder blades, which loosens the muscles around the shoulders and shoulder blades, and improves blood flow. * Quoted from the official website I purchased this because I have stiff shoulders and wore it 1-2 times. I have been storing it at home. Color: Black (appears bluish in the photo, but it is black) Size: M size If you don't mind, please consider purchasing.