250mAh battery capacity charging case can provide 3 times full charging for both earbuds. The nan-coating on the surface of the earbud can prevent water and sweat from penetrating, which can use as sports wireless headsets. The Digital LED power display outside of the case is to show the power level for the charging case. When you put earbuds into the case, the earbuds will start to be charged. After the first connection, these wireless earphones will connect with your device once you open the charging case, which is faster and more convenient. During use, you can touch either earbud to control the phone, such as the music switch, volume adjustment, phone calls, and voice assistant, etc.