Richard,
Blue Dots are regular tail light lenses that have a small circle of blue plastic or glass in the lens. When the brakes are applied, the lens "lights up" like with any other tail light. The blue insert gives it a unique purple glow. Most of the parts catalogs have pictures of both. If you go to
www.chevyduty.com you can type "blue dot" into the search window. A picture pulls right up. You can also type in the word "peep" and pictures of peep mirrors pull up too.
