It also includes a wide range of SMS functions to help you easily keep track of important people. * This product utilizes the highly accurate SiRF-Star III Chipset to provide reliable information. * This personal GPS tracker includes a built-in speaker and microphone which allows two way calling. * You can store up to three different numbers and then speed dial them with just a push of a button. * You can rest assured knowing that emergency communication is always ready no matter where you are.