This hearing aid is USB rechargeable, eliminating the need for frequent battery replacements. A full charge takes approximately 2 to 4 hours, providing up to 48 hours of use. It can be conveniently stored in a small case for easy portability. Suggestions: This hearing aid is USB rechargeable, so you'll never have to worry about replacing batteries. Choose an earplug that fits snugly in your ear canal to prevent noise caused by gaps. Wear the hearing aid correctly to ensure a close fit with the ear canal, preventing feedback and whistling sounds. Avoid touching the small speaker used for reception with your hands during use to prevent noise. Some noise is normal when using hearing aids for the first time. New users should select the low-frequency mode for the first one or two weeks and adjust it to the most comfortable volume to get used to wearing the hearing aid. Don't use it for too long each day. Take it off and rest every 30 minutes. After the adjustment period, try changing modes or wearing the device when talking to people, and continue experimenting in different scenarios until you find the most comfortable experience.