It consists of a finely balanced pendulum free to respond to any changes in speed or angle, working through a quadrant gear train to rotate a needle round a dial. The dial is black with silver white graduations and having a linear length of 5" (114 mm) with an easy to read lay-out. To damp out all vibration, the instrument is filled with a special fluid not sensitive to changes in temperature. No maintenance is necessary.

The dial is calibrated in percentage "G", the accepted standard throughout the world for measuring acceleration and deceleration. There are no connections to the vehicle other than mounting either with two self-tapping screws or the suction cup operated by the small side lever.

Calibration is now available in the USA.