Features :

• Accessory device only—requires an SN5127 or SN5147 to operate
• Super-loud extension ringer
  This extension ringer is designed to increase the ring volume of your amplified phone or doorbell*, or to be heard in rooms where there isn’t a handset. Carry it with you, or rely on the extra-loud, up to 90-decibel sound to alert you when you’re across the house. (*Feature requires SN7021 to operate.)
• Flashing LED visual alert
  A light on the cordless remote ringer flashes so you know if a call is coming in or someone is at your door, even if you can’t hear the system ring. This feature is ideal for the hearing-impaired.
• Wall-mountable
• Includes AC power adapter
• Adjustable siren volume