A:AnswerHello, Kathy! Please check the following link for compatible models for the additional handset: https://eng-ca.faq.panasonic.com/app/answers/detail/a_id/57170/kw/handset%20guide
A:AnswerHello. The phone system is compatible with the Caller ID service, you will need an active Caller ID subscription from the telephone service provider to use the features. -G
A:AnswerHello! The range of the handsets is 33 feet from the base unit. The range will also be influenced by the environment in which the phone system is placed, and if there are any electronics around that would weaken the signal (such as microwave ovens, Wi-Fi routers, radios). -G
A:AnswerHello. An additional handset can be purchased. Some compatible models are KX-TGEA60, KX-TGEA61, KX-TGFA61, KX-TGFA71, KX-TGFA85, and KX-TGTA61. -G
A:AnswerHello. The intercom can be used to perform calls between the handset. To use it, you have to press MENU, then choose Intercom, and select the number of the handset you wish to call. -G
A:AnswerHello. The volume can be reduced or turned off with the code MENU #160 on a handset. After entering the code, you will see the current volume, and you can reduce it by pressing the down arrow key on the handset until you reach the desired volume level. -G
A:AnswerKindly be informed that the speaker on this model is standard. If you would like a telephone with volume boost, we would recommend you to check out our amplified systems as well.
A:AnswerWe would be more than happy to look into it further. Please contact our Customer Service Team via Live Chat on the Panasonic Website, Contact Us option, Mon-Fri, 9am-5pm EST. -M