This recorder has all the great features of other digital recorders plus saves battery power. When used on your telephone, the recorder will power down when you hang up and power up when you pick up, which conserves battery life. The sensitivity to sound/voice can also be adjusted. Two Memory Capacities Available: DR7510 (or DR7510G with power adapter) and get 128MB of memory for up to 66 hours of recording time. DR75256 (or DR75256G with power adapter) and get 256MB for up to 133 hours of recording time. Features: Powers off when you hang up and powers on when you answer the phone to save power, Adjustable sensitivity and sound. Voice activated recording, USB interface, Microphone sensitivity adjustment, Repeated playback, Quick message search, Vibration mode for discreet recording, Time indicator for recording remaining, All in one menu button, Earphone allows for hearing aid use, File search plays first 7 seconds of each file, Auto power off when not in use, No Battery Drain works only when connected to a telephone. Includes: Digital Recorder, DVR manager CD, Ear Buds, Microphone, USB Cable, Telephone recording adapter, Telephone cord, Lanyard, 2 AAA batteries, Instruction book**Model Numbers ending in "G" also include AC power adapter. DR7510