Buyer Notice: Please be awared this model G200 is 2G GSM GPS Tracker. Please use sim card which support 2G GSM. If you are from Australia, Japan, China Taiwan, Sourth korea, Singapore, Canada or New Zealand, where 2G network had been closed, please consider our 4G GPS TRACKER G200L. If you want higher efficiency and faster communication tracker, please click to check out our 4G and 3G models. About Standby: G200 is built-in with 6000mAh lithium battery. The 60 days standby we claimed is based on a test of minimum use. For customers who use APP, SMS positioning, monitor, and alarms properly, tracker works for 1-2 weeks. Please use wall charger and charge the tracker for 12 hours each time. About IMEI: For customers from Turkey and Pakistan, you can change the device IMEI number by sending a SMS command. Any help needed welcome to contact us. Please Note: For Tracker has been upgraded. It needs to be activated by inserting SIM card.