Netgear Unite Pro 4G LTE Mobile WiFi Hotspot - GSM Unlocked DOES THIS DEVICE NEED A SIM CARD: Yes this device needs a micro SIM card, (Free from most GSM Networks with activation of an account) There will be a sticker with the Unlock code enclosed in case you need to reformat the device or change your Network provider. WHAT NETWORK FREQUENCIES ARE SUPPORTED BY THIS DEVICE: 4G LTE bands B17 (700 BC), B2 (1900 PCS), B5 (850). 3G Bands B1 (2100), B2 (1900 PCS), B5 (850). Which give it the ability to roam on LTE in many foreign countries, including all of Europe and much of Asia. HOW LONG CAN I EXPECT THE BATTERY TO LAST ME: Well it comes with a CADEX Tested battery with 4020mAh which in a Usage time means 16 solid hours of streaming at 4G LTE speeds as well it has a Standby time of up to 240 hours before you need to recharge the battery WHAT DOES UNLOCKED REALLY MEAN: Unlocked devices are compatible with GSM carriers the kinds that Use SIM Cards for Service like AT&T and T-Mobile as well as with GSM SIM cards (e.g. H20, Straight Talk, and select prepaid carriers) Unlocked Devices will not work with CDMA Carriers the kinds that don't use sim cards for service like Sprint, Verizon, Boost or Virgin (contact your network provider prior to purchasing for verification that they support GSM frequencies). !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! WILL NOT WORK ON VERIZON OR SPRINT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!