Audio-Technica ATH-CKS50TW Noise-Canceling True Wireless In-Ear Headphones (Black) - Manual (Page 11)

Part names and functions
10
Charging case
1
2
3
1 Cover
2 Charging indicator lamps
Light/flash when charging the charging case. Also displays the battery level of the charging case.
3 Battery jack
Use to connect the included USB charging cable and charge the product.