NuTone LA201 Door Buzzer, 3-Volt to 6-Volt DC

Great for use in commercial applications, especially at garage entrances, this buzzer will make sure you don't miss the delivery! Buzzer sound can be heard even in noisy environments. Uses transformer or 3 to 6-volt DC voltage, providing many years of service. Small size means a fit even in tight doorway entrances and offers a choice of installation locations. Metal cover keeps it safe from the elements to ensure reliable operation all year long.