I closely examined a couple of different safety triangles on the market and these appear to be of the highest quality.  They are heavy and for the most part that is a good thing (they don't fall over with big rigs etc going by) but it also adds to the shipping. The tabs that interlock the top of the triangle appear that they will hold up well. Look carefully at the shipping costs it can almost double the price even when going with the cheapest shipping method.