Hand-free device equipped with expansion function modules

摘要

A hand-free device equipped with expansion function modules allows a basic hand-free handset to attach expansion function modules depending on users' requirements so that the existing hand-free handset can be upgraded to equip additional or new function without obsolete. The invention consists of a hand-free main body and externally connected expansion function modules of various function desired. The function may be selected based on users' requirements such as GPS, PDA enabling, or audio control dialing, etc.