This is an 8421 absolute position encoder with 16-gear code(0-F). The mechanical position determines the uniqueness of each position of the encoder. Compared to a potentiometer, it doesnأ¢â‚¬â„¢t require memory, reference point and constant counting. Whenever you need the position, you can just easily read it. In this case, the anti-interference of the encoder and the reliability of the data are greatly improved. And because of the absolute uniqueness of each position, the anti-interference ability, and no power-off memory function required, this product is widely used in many kinds of industrial systems for device status controlling.