Embodiments include determining attributes of a property using an incubation pool. The plate member attaches to the surface and the product carrier releasably attaches to the plate member. The distributed feedback semiconductor laser is judged non-defective when the difference is more than a certain value. The stringer comprises a center mating surface and at least two outer mating surfaces. Furthermore, openings are formed in the wheel side flange at equal intervals and blocks having a threaded hole therein are pressed into the openings.