Power source: From Telephone Line In Panasonic KX-T7705 is able to show, when an outside call is being received, the phone number is displayed. This enables you to check who is calling before picking up the handset. You can use the speakerphone for hands-free conversations. Since you don’t need to pick up the handset, this enables you to do other work while having a conversation. The retention of 30 call logs makes it convenient to redial or check the call history.