The BEI Sensors/Sensata part 01002-8291 is an incremental rotary encoder with a 2.5" diameter. This encoder is part of the Express-H25 series and is known for its high accuracy and reliability. It offers a compact and robust design, making it suitable for various industrial applications where precise and consistent rotary motion monitoring is crucial. With its incremental output and easy installation process, this encoder provides a cost-effective solution for precise position and speed feedback.