The phones in the this section are all 4-line, analog telephones. This means they could be plugged into ordinary residential or small business phone jacks of up to 4 lines capacity. These phones will not work when plugged into proprietary digital extensions of business phone systems and may even cause damage to the system or to themselves if they are plugged into a digital-only extension. While a 4-line phone could theoretically be plugged into an analog extension, it would only work as a 1-line product in that kind of setup and is therefore unlikely to be appropriate as a business phone system extension.
Please note that the use of the phrase "digital extensions" here does not refer to internet phone services that provide an analog jack for telephone connection; it refers only to systems where the phone jack is producing a digital, rather than analog signal. If in doubt, please check with your system administrator or call THE PHONE SOURCE.
1-line office phones
OFFICE PHONES 
VoIP PRODUCTS 
