Many old incandescent trailer lights are bolted to the trailer with 46mm bolt spacing however many newer LED trailer lights have wider 70mm bolt spacing. I'd rather not drill new holes as my trailer is hot-dip galvanised so I printed an adapter itead. Tested and works well. I printed with an 0.8mm nozzle at 0.4mm layer height and 5mm holes for M4 bolts. It was fine but the holes where tight so I've uploaded a veion with 6mm nominal holes in the model for printing on large nozzles.