[Nuisance Call Blocker] - Avoid nuisance and unwanted calls. VTech's call blocker feature allows you to block nuisance calls and calls from unknown numbers. Block up to 100 blacklisted numbers. [Volume Booster] - Amplifies incoming sounds to enhance the clarity and loudness of the voice on the handset earpiece. Ideal for hearing-impaired users, or for those who prefer a higher volume level on the telephone. [Long Battery Life] - Up to 18 hours talk time / 250 hours standby time [ECO mode] - The handset automatically adjusts and minimizes radio frequency power according to the distance between handset and base unit. [MORE FEATURES] - Caller ID / Call Waiting (20 Records), Backlit Display & Keypad, Alarm, Mute, 10 Last Number Redial, 100 Name & Number phonebook, Handsfree Speakerphone & 3 Speed Dial numbers