The incremental hollow shaft encoder FGHJ 5 is a rugged device with large 40 millimeter bore encased in a stable, ribbed aluminium casing. The device is suitable for deployment in steel and rolling mills, in the mining industry, materials handling applications as well as on test stands. A shaft-mounted device with integrated bearings facilitates simple assembly without a coupling or need to center a flange. In addition, this concept results in a short assembly immediately behind rotating components such as a fan impeller. The incremental encoder FGHJ 5 utilizes a photoelectric scanning principle and supplies digital output signals with an amplitude that roughly correspond to the supply voltage. The encoder is insulated – by means of an insulated bushing and/or insulated adapter shaft or torque bracket.