This two-line version can handle incoming and outgoing calls for two separate phones and numbers.
It is meant for a small business that may want to receive calls on one phone and make calls on another.
Google Voice gives a free phone numbers, free home phone service, unlimited calling within the US and Canada, text messaging, and voicemail with transcribe.
As an alternative to using this box with a cordless phone, you download the Google Voice app on any Apple or Android smart phone.
The app can do incoming and outgoing phone calls over wifi, without paying for mobile service.
The Polycom OBi200 Voice-over-IP Telephone Adapter is on sale for $40.
Normally about $50-60.
The OBi200 connects a regular old telephone (or, cordless phone) with Internet-based telephone service.
Uses a free Google Voice account which includes a free phone number, free unlimited calling within the US and Canada, and voicemail with text transcribing.
Note that you can get the same free service by turning an old mobile phone into house phone, by using its wifi.
Without paying for mobile phone service or buying the Obi200, join your old phone to your home's wifi network, and download the Google Voice app.
Beware that 911 emergency service does not work with free Google Voice service, but E911 can be added onto the Obi200 for an annual fee of about $20 on the Polycom website when configuring your account. E911 is worth considering for the time-saving (and potentially life-saving) feature of transmiting your home address to dispatchers when someone dials 911 from your phone.