BATTERY STATUS INDICATOR - It signals when the battery is fully charged, ensuring you know when it's ready for use. RELIABLE AND SAFE - Incorporates an intelligent protective circuit and pressure relief valve to safeguard against overcharging, over-discharging, and short circuits USB-C RECHARGEABLE - These batteries feature built-in USB-C ports. The included four-split charging cable works with both USB-C and USB-A power outlets, making it easy to recharge all 4 batteries without a charger. RECHARGEABLE AA BATTERY 4-PACK - This pack includes four 2400mAh rechargeable AA batteries, a 4-split USB-C charging cable, and a storage case. Compatible with regular AA batteries, they make an excellent choice for everyday electronics, clocks, remotes, and more.