Netgear Unite Express 4G LTE Mobile Wifi Hotspot (AT&T Prepaid No Contract) DOES THIS DEVICE NEED A SIM CARD: Yes it does Being that this device is AT&T it will work on any AT&T Micro Size SIM Card, The sim card does not come included and you will need to contact your Network Provider to acquire your complimentary Sim card (Free from AT&T with activating of an account) As well 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: 700 (B17) /850 (B5) /1700 (B4) /1900 (B2) MHz As well as 3G Bands 850 (B5) / 1900 (B2) /2100 (B1) MHz. HOW LONG CAN I EXPECT THE BATTERY TO LAST ME: Well the battery has 2500mAh which in a Usage time frame means 10 solid hours of streaming at 4G LTE speeds with 10 WiFi-enabled devices as well it has a Standby time of up to 240 hours before you need to recharge the battery Easy Plug and Play Device will enable service on the go anywhere you Travel or Hike NOW REALLY WHERE CAN I USE THIS DEVICE: This device will work anywhere AT&T Offers service as well you may be able to unlock the device after 6 months of use by contacting the AT&T Customer Support Team.