GF - 07 Enhanced Magnetic Locator Preparation: Requires a SIM phone card and a mini memory card. "Can I use a 3G / 4G SIM card?" The GPS works with the 2G GSM network and supports 3G / 4G input, so you can choose a 3G / 4G SIM card, but it will only use 2G signals. Battery: 3.7V 400mAh Li-ion Standby Time: 12 days Working Time: 4 to 6 days Important Notes: 1. You need to purchase a GSM SIM card in your local area. 2. Each month will incur a data flow fee, approximately 50MB per month. 3. If you send a command and receive no response, please call the device. If it answers that the user is busy, it's okay. Then set the administrator number. If it goes directly to voicemail, please turn off voicemail. You can call customer service to turn it off, or you can turn it off in your phone settings. Package Includes: 1 x USB Cable 1 x GPS Tracker 1 x Instruction Manual (as follows) When you purchase this product, please contact customer service for instructions.