This refurbished no-contract modem is "like new" and is perfect for existing AT&T customers who want to swap to a more current device or need to replace a lost/broken device, but don't want to alter their contract (purchasing this device will NOT extend or alter your AT&T contract - once you get the new device, simply swap the SIM card from your old device to the new one). This device can also be used for AT&T's month-to-month service (you will need to contact AT&T after receiving the modem to sign up for service and acquire a SIM card). *the 313U has a standard-sized SIM slot - if you plan to use a microSIM, you'll need the micro-to-standard SIM adapter
You may need the AT&T Communication Manager to activate your modem - if you don't already have it installed, you can download it from AT&T's website
Refurbished devices fall under 3Gstore's standard 30-day return policy (read more at 3Gstore.com/rma). There is no manufacturer's warranty on refurbished devices.