A combination bell and buzzer provides a buzzer for the back door and a bell for the front door, all in one unit, (Fig. 6). Note that this unit has three terminal screws rather than two.
Follow the wiring arrangement shown in Fig. 6 for installing the combination bell-buzzer so the bell rings when the front door button is pushed and the buzzer goes off when the back door buzzer is pushed.
Always locate the bell and buzzer in a spot where the sound can be heard throughout the house. Bells and buzzers hidden deep in attics or closets may not be heard when they are sounded.