The dual bulb clearance or marker light in red is designed to conform to applicable US FMVSS108 and Canadian CMVSS safety standards for clearance lighting. The clearance marker is PC rated meaning that it can be seen 90 deg off from its center, helping to make your trailer more visible from all angles. The two-bulb design maximize light output and mounts on standard 3 in centers. The housing and polycarbonate lens are sonic welded to create a fully sealed light, extending the life of the light.