SN7021 Cordless Audio Doorbell for SN5127 or SN5147 Series Phones 

• Expandable to a total of 3 doorbells

• 2-way audio

• weather resistant

• Doorbell ringing LED

• Changeable chime

• Adjustable chime volume

• Wall-mountable

• Call divert to a preset phone number

• Depending on use, up to 1 year battery life on standard AA alkaline batteries (included)

• Support backup alkaline batteries (sold separately)

• Customizable and pre-recordable emergency message

• Door chime on CareLine handsets (sold separately)