It powers the built-in spy camera whenever the AC adapter is plugged into an outlet, while a lithium ion battery within records up to 3 hours of audio and video sans external power source. Data is stored on a microSD memory card (2GB max. which holds approximately 66 hours of footage) at 176 x 144 resolution in 3GP format, so you can forget about selling your voyeuristic tendencies due to such low resolution video.