The KX-TES824 Advanced Hybrid PBX System can cost effectively support all your personal and business communication needs. The system supports 3 outside (CO) lines and 8 extensions – all built-in so you can use the system straight out of the box. With optional cards, you can easily expand the capacity up to 8 outside (CO) lines and 24 extensions* as your needs grow. The system provides features that can satisfy the demands of the most sophisticated and cost conscious users. You can even connect a variety of communication devices, such as cordless phones, answering machines, computer modems, credit card verifiers, fax machines, and any other device that works with conventional telephone lines.