The optical sensor is great for a quick install since there is no need to remove the engine and install magnets in the fan. It does require a bit more maintenance to keep the lens clean so it reads correctly. It's good to have because of this. The Optical Sensor is supplied complete with reflective tape. Shown below, mounted to a OS C-Spec, the supplied adhesive backed reflective tape is applied to your clean fan. Sensor mounts to the brackets supplied with the Throttle Jockey Pro and RevMax.