Adopting high-precision inductive structure design and made of wear and corrosion-resistant material with accurate size and high coaxiality. The induction gear ring is evenly distributed with stable and accurate signal collection and sensitive induction of rotational speed and gear position without deviation. Compatible with transmission speed signal acquisition system, it features anti-interference, high and low temperature resistance and vibration resistance, keeping signal free from drift and error under complex operating conditions. With original interchangeable specification and easy installation, it effectively solves faults such as abnormal signal and instrument error.