1. This battery box has XP7 waterproof function. 2. There is no need to spot welding the battery, which greatly reduces the internal resistance of the battery and improves the battery discharge performance, thereby effectively increasing the battery life. 3. Easy to use, using 3 18650/26650 lithium batteries. 4. With DC connector input and output voltage of 16.8V. The USB connector has an output voltage of 5V and a current of 2A, which can charge the phone. (The voltage of battery input and output has an error of ??±0.2V) 5. With power display function. (3LED indicator light) 6. Net weight: 220G 7. Gross volume: 260G 8. Ruler inch: 95X64X64mm Battery specifications: 18650x3/26650x3 Specifications: 1. Input voltage: 16.8V 2. Overcharge protection voltage: 16.8V 3. Over-discharge protection voltage: 8.4V 4. Over-discharge protection current: 9v 5. Standby current: 80ua 6. USB maximum output: 2000ma Note: The first time you insert the battery or turn it on again, you need to connect the 16.8V charger and charge for 3-5 seconds to activate (The battery needs to be aligned with the positive and negative poles, otherwise it will burn the battery box) 16.8V battery box: Two interfaces, 16.8V can output and input, 5v output, can be put into 18650/26650 as a charger, can be used as a portable battery box, charger, power for bicycle lights, USB lights, 16.8v LED lights, etc.

http://olla.gr/3-sections-18650-26650-ipx7-waterproof-battery-box-with-16.8v-round-head-and-5v-usb-connector-output-voltage-does-not-include-battery-black/