Built-in large capacity rechargeable lithium battery and can be used for 15 days after 2 hours of charging. The switch has an indicator light, constant red light indicates charging, and constant blue light indicates full/normal operation. Invisible use for all people: the top straightening belt is compact in size which It can be worn under your clothes invisibly without anyone noticing, you can wear it at home, work, study, outdoors, office, shopping in any other occasion. Adjustable harness for children and adults, men and women. Efficient scientific correction: We recommend that the user wear the posture corrector for 2 hours a day. 21 days is the period of habit formation, and the posture will be significantly improved, 90 days of persistence will enter the period of habit stability. Smart Posture Corrector: The intelligent posture corrector will vibrate the alarm automatically to remind the user when your back is bent forward more than 25 degrees, help you correct bad posture habits, keep you upright and more secure. Comfortable to wear: the nylon cloth material High elasticity is comfortable to wear without pressure on the shoulder and fits the curve of the human body. The shoulder straps can be adjusted to your most comfortable length.