Set the posture corrector to maximum size. Carry them like a backpack with the Y alphabet facing up. Adjust the position of the strap and tighten the strap. Make sure it is comfortable and enjoy. You may experience some discomfort or tightness on first use. We recommend you start wearing 20-30 minutes the first time, then increase wearing time until you are completely comfortable wearing your posture support. Easy to use. Set the posture corrector to maximum size. Carry them like a backpack with the Y alphabet facing up. Adjust the position of the strap and tighten the strap. Make sure it's comfortable and enjoy. You may experience some discomfort or tightness upon first use. We recommend you start wearing 20-30 minutes the first time, then increase wearing time until you are completely comfortable wearing your posture support. Size chart:L 95cm-110cm waist