Universal Portable Phone Amplifier- Model UA-30

Hear landline calls clearly wherever you go.

Easy-to-use phone amplifier straps to any handset. Boosts incoming volume up to 26+dB. Tone Enhancement improves speech clarity. Compact, lightweight, portable design. Include two AAA batteries and a carry pouch. Amplifies the other caller’s voice up to 26+dB louder. Advanced Tone Enhancement automatically optimizes speech clarity for improved understanding.

Source:- https://www.sereneinnovations.com/universal-portable-phone-amplifier.html