"Posture Trainer: Our updated posture corrector is equipped with smart sensors that vibrate to alert you when you have poor posture. If you wear our posture corrector for a period of time, you develop muscle memory. This means You'll stay straight in the future, even without the trainer device. Feel more confident in your life^ ADJUSTABLE SIZE: There is a durable adjustable buckle that makes it adjustable to chest sizes 23 to 42. It fits adults (men and women) and children because of its adjustable size. Do not hesitate to use this orthotic to maintain good posture with your partner. ^Easy USB Charging: There is a USB charging cable in the box. It can usually be used 15 days (15 minutes/day) It only takes about 2 hours to charge and you can take it with you. There are 4-level indicators on the display to show the battery level: 1 star - 25% charge, 2 stars - 50% charge, 3 stars - 75% Battery, 4 stars - 100% charged. It is very convenient to know the battery level directly through the light. ^Lightweight and stylish design: The beautiful and lightweight design makes it possible to live inconspicuously under clothes at work or daily wear. Recommended for those who suffer from long-term sitting at the desk People with hunchback, sore shoulders, and lower back discomfort. It is also a good choice for your children to maintain good posture and healthy habits. ^ Good Gift Choice: The universal size posture corrector is not only suitable for men and women; Children. Fits the back spine, helps the spine reset, pulls the shoulders back, prevents and improves hunchback. Use it as a posture trainer for at least 30 days, and you will find that you are in good condition. Enjoy a healthy life with your family and friends."