wireless Bluetooth 5.3 in ear transparent earphones

Bluetooth version: Bluetooth 5.3.Transmission range: 15m.Music time: approximately 7 hours. Call time: approximately 4 hours.Total working time: approximately 25 hours. Rechargeable case battery: can charge the earphones 4 times. Headphone charging time: approximately 1 hour. Charging time for the charging case: approximately 1.5 hours. Single earphone weight: approximately 11g..One Bluetooth earphone is not working:1. Check if the set mono output can be adjusted to two ear channels.2. Check if the battery of a headphone is depleted.3. Check if the two headphones are connected to both devices. You can close the connection and remove the Bluetooth earphones from your phone's Bluetooth list. Pair your phone again and then play the audio again. One Bluetooth earphone is not working:1. Bluetooth earphones are left for too long. If not used for a long time, the lithium battery inside the earphones will be in a "sleep" state. As long as the charging time exceeds 30 minutes, the earphones will display the charging status.2. The earphones haven't been used for that long, and they don't show up even after charging for over half an hour. Check if the headphone charging cable plug is damaged. You can try other data cables or check if anything is blocking the charging point of the headphone. If available, please clean with a toothpick