VTech DS6251-2 Dect_6.0 2-Handset 2-Line Landline Telephone, BlackFeatures 2 Line operation, caller id call waiting stores 50 calls 1, 000 name and number smart call block directory stops unwanted callers. Call intercept. Volume control Expandable up to 12 devices (2 devices can be cordless headsets model is6200) with cordless handsets model ds6250 2 digital answering systems (one per line) w voice guide up to 22 minutes of recording time Full Duplex handset and base speakerphones. Message retrieval from handset