Uniden DECT1080 DECT6.0 Expandable Cordless Phone with Digital Answering System and Call Waiting/Caller Id DECT 6.0 Interference Free Cordless Frequency - (1.9 GHz Digital Enhanced Cordless Telecommunications) V-Quad Technology (4 Way Voice Enhancer) and Conference Call - You can hold a 3-way conversation (conference call) between your handset, an external caller and another internal handset user. Handset Speakerphone - This feature gives you the freedom to use the handset as a speakerphone. Digital Answering System - The product utilizes microchip technology (no more tapes or moving parts.) This ensures clearer recordings and longer life. Expandable - Register 6 Handsets to 1 Base