Every word will come across loud and clear. It's easy to install and it is portable so you can take it anywhere. Simply unplug the handset cord from your telephone base and insert it into the jack at the front of the Telephone Amplifier. Plug the Telephone Amplifier telephone wire into the handset jack on your telephone base. Pick up the phone, switch the Telephone Amplifier on and your all set. Enjoy loud and clear calls without a hitch. Requires (1) 9-Volt Battery to operate ( not included). Cannot be used with cordless phones.Covered under a 1-year mfg. Warranty
Product dimensions (imperial): 1.5 inch H x 2.25 inch L x 3.5 inch W
Product dimensions (metric): 38.10 mm H x 57.15 mm L x 88.90 mm W.

Product Features:
• Powerful adjustable amplifier will increase your telephone's volume up to 35 times
• On/Off switch so hearing and hard-of hearing members can both use the same telephone
• Requires (1) 9-Volt Battery to operate (not included)
• Low Battery Indicator flashes when battery is low
• *Cannot be used with cordless phones*