The posts are 6 x 6 off the shelf PVC posts although you could make them up out of wood.. The wood rails are mahogany 2 x 4's The cable is not continuous around the corners. I believe the most recent cable we installed said the longest run was 40 feet. That might be different depending on cable manufacturer.

Thank you Peter. I's a beautiful result!!

Peter - beautiful work - love the aesthetic/simplicity. When you say off the shelf PVC, do mean product similar to Trek, etc?

It is more likely a Koma or Azek product. Most lumber yards should be able to supply these