You'll need a controller to tie the doorphones, electric doorstrikes and PBX together. My preference for this is the
Viking C-1000a .
Of all the compatible doorphones made for that controller, my choice is the
E-30 . It looks sharp and is vandel resistant. Use the E-30-EWP (Enhanced Weather Protection) version if environmental exposure is a consideration. If cost is a factor, you could use the
E-10 doorphone instead. It has a black wrinkle finish and can also be ordered with Enhanced Weather Protection.
The doorphone's specsheet indicates a 4x4x2 wall opening for installation. Though that is a standard size for an electrical junction box, DO NOT install one as the screw holes won't line up. Instead, provide an opening large enough to accomodate the rough-in box that comes with the doorphone. Use an appropriate adhesive or concrete anchor to secure the back of the box against brick or concrete.