Unless someone came out with a 3rd back-up lens, there's only 2 that I've ever seen. The original that came with the PT and these...
Both lenses (OEM and the ones above) have the mandatory-by-law 2 square inches of reflective red lens. An all clear back-up lense would not pass inspection (if your state has inspections) unless you hade some other reflective red lens somewhere else on the rear of your cruiser.