[. . . ] [. . . ] Voice/Sound Activation The MHA100 turns on and off automatically to help conserve battery life. Easily Connects Between Phone and headset This amplifier works with most mobile and cordless phones with a standard 2. 5 mm headset jack. (Headset not included. ) Power Requires three AC675-type standard hearing aid batteries (included). · · · Product Order Specifications Model No. Unit UPC Code US Quantity Package Dimensions Weight Case UPC Code US Quantity Dimensions Weight Master Carton UPC Code US Quantity Dimensions Weight Pallet Quantity Country of Origin MHA100 0 17229 11686 3 1 9. 15"W X 5. 75"D X 1. 25"L 0. 206 lb. [. . . ] [. . . ]