@soch
You do not need 12V !!!!
Please read the manual first because it is very dangerous to work
under the impression that some phones need 12V power ;-(((
http://www.advance-box.com then click SUPPORT.
Then, after reading the manual,, you can ask more specific questions
pertaining to the phones that you currently have on hand so we can
do some actual testings.
Best Regards,
X-Shadow