There are 2 ways to install your blocker (please refer to manual). There are Pros and Cons of each setup, as follows:

Series Installation:


Pros:

- You may not hear any rings when a blacklisted number calls you.
- You don’t need to change your setup to program your T-Lock.


Cons:

- You may lose the Caller ID info on your existing phones. This happens with many phone services due to the fact that this unit is line powered and there is not enough signal strength on your phone line to pass the caller ID info to the phone(s).

Parallel Installation:


Pros:

- You will be able to continue receiving the caller ID information on your existing phones.
- If you have low power on your phone line, this setup will work better for your existing phones.


Cons:

- You still need to connect a handset to the ‘PHONE’ socket in order to program your T-Lock.
- Also, you will hear 1-2 more rings when blacklisted numbers call you.

To learn more about series and parallel, please read the manual.