It is a portable charger.
Portable chargers can provide power of smartphone,tablet etc. When your smartphone battery is lost,you can charge from it.
If rental WIFI device battery would be empty you need to charge battery and search concentric plug in Japan,
Unfortunately it is difficult to find concentric plug in public, If you have a sub battery, it solves this problem!
Rental companies provide insurance for rental device.
It is system of optional insuranse.Compensation fees will be discounted or waived in case of loss, theft or a damage of
device with enrollment in their insurance plan.The compensation fee,details,etc depending on the company.
No you can't.You can sign up insurance when you book it only.
You can't sign up an insurance during using or after returning a rental WIFI.Please attention it.
Please contact a rental company immediately.
It makes WIFI from Cable Lan of Hotel.
When you connect to cable and Lan Cable of Hotel,the device provides wiress Lan environment.
This is the charger from cigarette lighter socket of car.
If you ride a car in Japan, we recommend you rent this device.