● Amplifies call volume by up to 30dB. ● Features an automatic power-off function to turn off automatically. ● Easy installation, no construction required! (Only compatible with phones that have a modular handset) This item has been used, so it is not in new condition. Although it may be difficult to see in the photos, there are some sun-fading marks on the side. It was working without any problems, but I no longer need it since I replaced my phone with a cordless one. I would like to give it to someone who needs it. I did not keep the packaging, so I will include a printout of the instruction manual from the manufacturer's website.