You'll often see these purple lights mounted on underside of tractors or trailers; purple/violet light allows driver to see beneath trailer without degrading night vision or being distraction to other drivers. Also available in Red and Amber. Dimensions: length overall 3" x 1" x 1", lens only 1-3/4" x 7/8"H x 1"; weight 0.6 oz. Excellent quality - made in Taiwan. Sold individually; order in quantities for your application (shipping charges calculate automatically).