Excellent product for making a Pergola out of 4x4's. We had thicker plus-shaped plates custim-made in the same style, so we could add a 4x4 railing that would not twist. These days, outdoor lumber is sold too wet and too green, so it twists with mighty force. The TOJA GRID products are strong enough to hold them in place, but they only make the end joint brackets (as of 2020). One day I hope they will see the wisdom of making mid joint brackets, basically the same product but without the end stop inside it that prevents the 4x4 pushing through the bracket. If they do start making mid-brace brackets though, they would have to be thicker plate and that would create a style mismatch with the existing product. So, if you make your own 4x4 brackets for mid-way mounting 4x4s such as with railings, don't forget to make them much thicker, and not wider than the flat surface of the 4x4 which is only 3-inches.