- Cortelco Colleague corded single-line telephone- 90V Message waiting lamp- Handset volume control- Hook delay (positive line disconnect)- A-lead control- Data jack- Hearing aid patible- Hold with LED indicator (flip-flop type)- Last number redial- Flash (100-300-600mS) switchable- 10 One-touch programming memory- Mute with LED indicator (flip-flop type)- Speakerphone with LED indicator- Headset control switch (does not have headset jack)- 1 Year manufacturer"s warranty- BlackITT2203BK