PG88 Single Core Wrist Quad Band Watch Phone with GPS, MP3, Bluetooth, FM. Highlight: Make sure the SIM card is a standard GSM network card. Make sure the GPRS functioning properly. Make sure the account of SIM card has enough money. Make sure the SIM card does not set a password (PIN1, etc.). Check the SMS inbox, if full, propose to delete some, otherwise can not receive GPS tracking SMS. Check the SIM card is opened the Caller ID features. If not support caller ID feature can not find the target location when hang up calls and monitoring functions. Contact your telecom carrier for APN information and setting on the device. The factory default APN setting is CMNET. Before tracking on the platform, please use the cell phone set up the guardian number and related instructions. So buy this product and Get 60% OFF PG88 Quad Band Watch Phone.