TALKBACK BUTTONS; UP TO 56 DB AMPLIFICATION AT 124 DB SPL; 8 VOLUME/TONE AMPLIFICATION LEVELS; 3 FREQUENCY-SPECIFIC AMPLIFICATION SETTINGS: NORMAL EXTRA;AMPLIFICATION FOR HIGH FREQUENCIES OR LOW FREQUENCIES; AUTO-SELECTS THE BEST AMPLIFICATION LEVEL; CONCAVE EARPIECE FOR BEST CLEAR SOUND; HEARING AID COMPATIBLE; 30 DB EQUIVALENT AMPLIFICATION WITH HANDSET FACING DOWN 26 DB WITH HANDSET FACING UP; 2.5MM HEADSET PORT & 3.5MM NECK LOOP PORT; 95 DB AUDIO VISUAL & VIBRATING; BIG BACKLIT NUMERIC BUTTONS; COLOR-CODED FEATURE BUTTONS; TALK SPEAKER OFF REDIAL & MEMORY; SWAPPABLE RECHARGEABLE BATTERIES IN HANDSET; OPTIONAL SWAPPABLE RECHARGEABLE BATTERIES IN BASE; WALL MOUNT OR DESK MOUNT; INCLUDES AN AC ADAPTER & A 12-FT LINE CORD; BLACK