DESC: The Super Phone Ringer generates a loud ring to let you know when a call comes in. With Adjustable volume and tone control, you will never miss a call again. * 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 * Dual modular phone jacks for easy plug-in connection * No battery necessary, powered by telephone line