Zte Maven 4G LTE Android 5.1 Lollipop Mobile Smartphone GSM Unlocked 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, 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 BY THIS DEVICE: The Phone supports the folowing Technology Technology GSM / HSPA / LTE 2G bands GSM 850 / 900 / 1800 / 1900 3G bands HSDPA 850 / 1900 / 2100 4G bandsLTE band 2(1900), 4(1700/2100), 5(850), 17(700) Please contact your network Provider and inquer if they support these bands in your area to ensure the device will work Properly WELL, HOW LONG CAN IT LAST ME: A removable 2,100mAh battery that lasted for 10 hours of continuous streaming in our tests. as well as 360 hours in Standby mode. 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 necessarily support CDMA Carriers the kinds that don't use sim cards for service like Sprint, Verizon, Boost or Virgin, it's always best to contact them prior to purchasing to confirm their compatibility on the bands supported by this device. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! WILL NOT WORK ON VERIZON OR SPRINT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!