SmartSound Motion Activated Sound Player Motion sensor triggered audio playback with detection range up to 16 (5m) Adjustable sound volume Incorporates 4MB internal flash standard, or up to 4GB if the microSD card is left in the unit (required to change MP3 files) Two working modes: Loop through each sound file or repeat a single file when motion is detected Comes with internal rechargable batteries and an AC power supply. NOTE: MicroSD card not included!!