• Mobile Wi-Fi rental service in Japan.

size	70.5(W)×22(L)×56(H)mm
weight	168g
fee	163YEN per day

External battery is a portable recharagable battery, you may charge the Wifi-router anytime at anywhere.
Simply plug the USB cable to the Wifi router to charge.,
You may also charge your own smartphone or tablets.
It is recharagable so you may recharge it at home or hotel.