ZTE Velocity 4G LTE Mobile WiFi Hotspot GSM Unlocked - White DOES THIS DEVICE NEED A SIM CARD: Yes it does Being that this device is GSM unlocked it will work on any GSM Network with a Micro size SIM Card The sim card does not come included, FYI Firmware Updates will only be available over the Air with an Active AT&T Sim card if you will be using this device with a Network Other than AT&T you will need to contact your Network Provider to acquire your complimentary Sim card (Free from most Carriers with activating of an account). WHAT NETWORK FREQUENCIES ARE SUPPORTED AND CAN BE RECEIVED BY THIS DEVICE: LTE bands 2/4/5/17/29 and UMTS HSPA 850/1900/2100. As well this device can provide WIFI: Dual-Band WiFi (2.4GHz or 5GHz) This variation of bands 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 the battery has 2,800mAh which in a Usage time frame means 10 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 CAN I EXPECT OUT OF THE BOX: Well this device has a Single-Core Qualcomm MDM9225 Processor giving it the ability to Connect up to 10 devices simultaneously with Separate Guest WiFi to ensure security as well it will come with a charger and a manual all you need to do is insert your active sim card and you are good to go. 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).