H-503 Headset telephone
1. Clear and distinguishable for speech sound
2. FSK/DTMF dual system auto switch
3. 62 group Caller ID message memories
4. 16 group outgoing message memories
5. 3 group one-touch dialing memories
6. 5 digit of local area code
7. Flash time 100/300/600/1000ms selectable
8. Music on hold function
9. 5 levels of LCD contrast adjustment
10.12 digits of number of incoming call display
11.15dB speakerphone volume control
12.Ringer of outside and inside option function, incoming call indication
13.In use indication
14.RJ-11 and 2.5mm jack
