Expand your existing AT&T TL86103 phone system with the TL86003 accessory handset to ensure that no matter where you are in your home. The TL86003 also allows you to download up to 6,000 cellular phonebook entries into the cordless handset. The handset notifies you when your Android mobile phone receives texts, e-mail or social media updates as well as calendar reminders through you TL86103 system.