The posture corrector helps to keep the shoulders back, strengthening the postural muscles and promoting oxygenation. It also provides relief from poor posture. The vest is virtually undetectable and can be worn either under or on top of clothing. The posture corrector vest supports the upper body and steers its position in the right direction, which in turn helps your muscles to stay more relaxed. The vest can help relieve tension in the neck and shoulder area, for example.Size chart: S/M - Height: 150-175cm - Weight: 50-70kg M/L - User height: 155-185cm - weight: 65-85 L/XL - User height: 170-195cm - weight: 80-105kg Product information: Sizes: S/M, M/L and L/XL Material: cotton, nylon and elastane.