The main base is the central communication for all the handsets, if your main base station is faulty none of your handsets will work.
BT 4600 Cordless Phone, Twin Handset with Big Buttons Home Phone Answer Machine
BT 4600 Cordless Phone Additional Expansion Handset
BT 4600 Cordless Phone Additional Expansion Handset BT4600
BT 4600 Cordless Phone Add-on Additional Extra Replacement Handset Only
BT4600 BT 4600 Cordless Phone Replacement power supply / adaptor only "066270"
BT 4600 Cordless Phone, Twin Handset with Big Buttons 6 month old Answer Machine
