Clarity XLC3.4+ DECT 6.0 Extra Loud Big Button Speakerphone with Talking Caller ID 4 tone settings for a customized listening experience & 95dB extra-loud ringer with adjustable tones Amplifies incoming sound up to 50+dB & outgoing speech up to 15dB for others to hear better Includes dual-power battery allowing calls when power is out & belt clip High-contrast Caller ID screen with large font & talking Caller ID Hearing aid compatible & TIA-1083 compliant Amplifies incoming sound up to 50+dB & outgoing speech up to 15 dB for others to hear better DECT 6.0 technology for interference-free communication Includes 4 tone settings for a customized listening experience & 95dB extra-loud ringer with adjustable tones