AT&T ML17939 ML17939 Two-Line Speakerphone with Caller ID and Digital Answering System ATTML17939 ATT ML17939, Perfect for small businesses that need two-line support plus other common telephone features. Fully integrated answering machine makes it easy to screen calls and check your message while away. Large, easy-to-read display clearly shows phonebook entries and Caller ID information. Compatible with most headsets (via 2.5mm jack) and hearing aids. Answering System: Digital; Lines: 2; Telephone Type:orded; Caller ID/Type: Standard Display., UPC 650530019715