Advantages: 1・ this battery box with XP7 waterproof function. 2・ do not have to spot the battery・ so greatly reduce the battery resistance・ improve battery discharge performance・ thus effectively improve the battery life. 3・ easy to use・ you can use four or six 18650 lithium battery. 4・ with DC connector input・ the output voltage of 8.4 V. USB connector output voltage 5 V ＼ 0.2 V・ with the phone charging function. 5・ overcharge protection voltage: 8.4 V・ over discharge protection voltage: 5.0 V・ over discharge point protection current: 9.0 A・ standby current: 10 A・ 6・ with power display.