The P2453BTA is the only Prizmalite microsphere made of barium titanate glass. Barium titanate glass has a higher Refractive Index [RI] than soda lime glass: 1.9 compared to 1.5. The Refractive Index of a material measures the degree a ray of light bends when it moves from one medium to another. Its practical significance is that it indicates how light will reflect back to the viewer. Barium titanate glass with its higher RI will reflect back more directly to the viewer than soda lime glass, which will scatter to some degree. This direct reflection is particularly important for applications when retro reflectivity is desired such as guard rails, traffic signs or reflective tape or clothing.

The P2453BTA microsphere is hemispherically coated with aluminum. The light bouncing off the aluminum-coated half of the sphere produces the retro reflective effect that provides the desired high visibility in dark conditions.