Stop struggling to hear your caller when you're using your phone in noisy environments; our cell phone amplifier makes incoming calls up to three times louder. The lightweight device connects between your cell phone and your headset (not included), and is voice-activated, so theres no fumbling with an additional power switch. It amplifies the high frequency sounds that are the most difficult to hear when you're in surroundings with high levels of ambient noise. The adjustable volume control can make incoming sounds up to 24 dB louder. Our cell phone amplifier works with all standard 2.5mm jacks, including those on many household cordless phones. Includes belt clip and three hearing aid batteries that provide 30 to 40 hours of talk time. 2 H x 11/2 W x 3/4 D. (3 oz.)