The part number for this item is Rigid Industries 110944 and it is a Rigid Industries Protective Polycarbonate Cover for Rigid E Series, M Series, and Radiance Series (Double Row) LED Light Bars (Amber PRO).
Please note each cover is 10" Long. If you have a 20" E, M, or Radiance Series light bar you will need to order qty 2, qty 3 for a 30" and so on.