More from Amazon.com : http://www.amazon.com/gp/product/B000E9U980?tag=purrfectcatdi-20

Clarity SR-200 75180 Super Phone Ringer w/ AC 95dB WH

Designed for people with moderate to severe hearing loss
Adjustable ring volume control up to 95 dB
Adjustable ring tone control to best suit your hearing
Four selectable ringing patterns
Bright visual ring flasher