The CEA-70 Loud Indoor Bell makes it easier to know when your phone is ringing.
It features an extra audible alert if you are having problems hearing your telephone ring.
It simply plugs into a spare telephone socket or a double socket adaptor beside your existing phone – it does not require mains power.
Telephone lines usually have a REN of 4 ~ they can operate up to four telephone products (e.g., phones, fax, answering machine) each with a REN of 1. The Bell 50E has a REN of 1.