1. Specical and Only for 6*18650 Li-ion rechargerable battery ( with protection PCB),please install same battery capacity for usage
2. 8.4V DC input and output, 5V for USB output to charge mobile phone faster
3. Waterproof Grade is IP67
4. Magic strap to ensure installtion more convienent and faster
5. Please KINDLY TAKE NOTE: ONLY ONLY SUPPORT SAME VOLTAGE, SAME INNER RESISTANCE,SAME CAPACITIY TO PUT inside the pack, thanks.