1. Measure the length of your torso and determine the size before . The strap of our product is elastic and stretchable. There may be some discomfort at first, but it will improve after several uses. 2. GOODBYE, BACK PAIN. HELLO, BETTER POSTURE – This fullback posture corrector is here to help you sit and stand taller! Its figure8 design slips on like a backpack, gently encouraging your upper back and shoulders into proper alignment, relieving pressure, strain, and tension while straightening rounded shoulders and a forward head posture. Just one hour a day helps! 3. RELIEVE SHOULDER AND NECK PAIN WHILE WORKING AT THE COMPUTER – Our back posture corrector can keep your back straight and shoulders pulled back. Do you spend all day sitting at a desk or standing while lifting and bending constantly? Do your shoulders hunch, causing neck stress while sitting at the computer or driving? Our amazing fullback brace will help you stay upright whether sitting or standing. 4. UPPER BODY SUPPORT THAT STILL LETS YOU MOVE – Gardening, cleaning, driving, mowing the lawn, carrying groceries—sometimes your back needs a little extra help to get things done. This back posture corrector is lightweight without sacrificing support, so you can sit, drive, walk, lift, twist, and bend with proper alignment.