The LowPro 23/05 plastic road plate has been improved to be HS20-44 mpliant up to 4′ trenches – this product is yellow and blue. Mark 1 version of the LowPro 23/05 Road Plate is no longer available, it is yellow and gray and is HS20-44 mpliant up to 3′ trenches. Quieter, long-lasting, lighter alternative to steel trench plates.