I was using this with a Rakuten Mobile SIM card. The settings are currently configured to work with Rakuten Mobile, so you can use it simply by inserting your Rakuten Mobile SIM card after the product arrives. The image shows the device with a Rakuten Mobile SIM card inserted. Included: Main unit only (operation confirmed) Initial username for the management screen: "admin" Password: "22543" (last five digits of the IMEI) *Automatic update setting is turned off. *If you perform updates or a full reset, the supported bands will change, and it will no longer be usable with Rakuten Mobile. Please do this only if you have the necessary knowledge.