Comet Series Perfect Prox Diffuse Reflective Sensor by Cutler Hammer Eaton. The advanced optics and high power of the Perfect Prox allow the sensor to reliably detect an object at maximum range regardless of the object's colour or texture. In addition, the sensor has a unique ability to ignore objects just outside the maximum range (This is known as the cut off range). The product is a modified version of 13108A6517. There is less variation in its maximum range. The maximum range is specified to be no more than 7.5 inches when detecting a 90% reflectance white test card. In addition, the sensor has been adjusted for dark operate and the light/dark adjustment pot has been sealed over. The cable length has been extended to 4 meters.