The Geemarc Telephone CL100 is an easy to use big button telephone , fully hearing aid compatible and is Europe's best selling Amplified telephone. It has a receiving volume of up to 30dB making it easy to hear and tone control means you can adjust the pitch of the receiving sound to customise it to your hearing loss. The maximum ringer volume is up to 85dB. The CL100 is powered by telephone line only, so there is no need for an electric socket to enjoy all the functionality of this popular amplified phone. The additional features of the phone include: 3 emergency dial buttons. You can program these buttons with the emergency number of your choice. There are 9 one touch memories, which will be retained even if the telephone is disconnected .The extra bright flashing light signals that there is an incoming call . The top right hand corner of the phone has the Amplifier on/ off button. You can have the telephone set so that when you pick up the handset the phone is amplified or you can have it set at regular volume. If your voice is a little weak then the CL100 has an outgoing voice amplifier to give your voice a little boost. Set the volume level by moving the volume slider (High-Low, OFF). You can also adjust the tone of the call, so that you can amplify the low or high frequencies according to your needs.