Size Chart: S: Suit for weight: 20-40KG M: Suit for weight: 40-80KG L: Suit for weight: 70-110KG Package included:1 x Back Corrector Features: 1.ADJUSTABLE SIZE:4 Size Available. Back Posture Corrector with Breathable and Latex-Free Adjustment Strap. 2.OVERALL CORRECTION:Shoulder Support Brace Pull back your Upper Back to the right position. And then improve your whole body posture during work or life. 3.USE ANYTIME:You Can Use it When you are Sitting on Computer/Driving/Playing Sports/Gardening/Doing Housework/Watching TV. 4.PRACTICAL:Posture Brace Filed with Lightweight Neoprene,Can be Worn Comfortably Under or Over Clothing.Correct your posture all day.You Can Put on and Adjust by Yourself. 5.USE DAILY:This Lightweight Back Support Should be Worn Every Day. First Couple of Days Wear it for 10-20 Minutes only, than add 10 Minutes Every Day. Your Back and Shoulders Will Adjust slowly and you Will Build Muscle Memory for the Right posture. Note: Our Products are Recommended for Adult Male/Female use, and Children Should Try to Avoid Using them as Much as Possible to Avoid Causing Physical Discomfort to Children.