This is an injection molded acrylic replica of the original LED bubble strip element of an Exactra 19 or 20 calculator. It measures 51 x 15 mm, so it is a bit wider than a real bubble strip to fit better in a Graflex or MPP style clamp. The bubbles are crystal clear and nicely polished. The front surface around the bubbles is slightly matted, just as in the original part. The strip might need some adjusting to fit a clamp.