Wide Compatibity: suitable for C-battery specification equipment, such as high-power flashlights, remote-controlled cars, medical instruments, etc. with a free storage box for convenient storage Fast Charging & Convenient Charging OptionsCharge your D batteries quickly with USB-C, USB ports, or power banks. The included USB-C cable allows fast charging for immediate use. Long-Lasting & Eco-Friendly:These 1.5V rechargeable D batteries are free from harmful materials like mercury, cadmium, and lead, making them an eco-friendly choice. With a capacity of 4100mAh, they can be recharged up to 1200 times. LED indicator easy to monitorThe LED indicator shows the charging status (flashing green when charging and always bright green when fully charged).