Using the NXT Brick (sold separately), the Accelerometer Sensor lets your LEGO® MINDSTORMS® creation know which way is up and when your robot tilts left or right, up or down, or side to side. This three axis accelerometer sensor also measures acceleration so you can measure g forces just like jet fighter pilots and astronauts. Does not include connector cable. This is the individual component, and does not include the NXT Intelligent Brick, software or any accessories. It requires the complete LEGO® MINDSTORMS® NXT set (#8527 or #8547) for use.