RAY OPTICS KIT Kit consists of two lamps and two stands, 1 pair housing shields, 2 combined single and triple slit plates, 2 multiple slit combs, 2 holders for combs and slit plates, 4 wooden light barriers, four each Plano convex cylindrical lenses, 50 x 50 mm, respectively. Plano convex +10D, +17D, Plano concave