Safety of materialsBattery case and not pluggable to 220V mains. Our products are made of non-flammable ABS materials and are used with confidence. Access reminder When someone a visit your home or office, through our wired doorbell, you can know someone is visiting to prevent bad people from entering. Easy to InstallThis doorbell is easy to install. install, but you need to replace or modify the battery. Power The doorbell requires 2 AA batteries (not included) Power The doorbell requires 2 AA batteries (not included) ) Product Description 90DB Wired Door Bell Welcome Wired Gas Bell Burglar Alarm Doorbell Alarm for Home Office Access Control System Reminder d 'access When someone is going to visit your house or office, you can know that someone is visiting to prevent bad people from coming. Easy to install< /p> This bell is easy to install, but you need to replace or change the battery power supply The bell requires 2 AA batteries (not included) Replace the old bell This bell is the best alternative to the old and broken bell.