The insulators look like they are just sitting on there but they are attached. Two long deck screws, placed just far enough for the pinhole to slide over, work very well. They seem to stay on OK and have been through some strong windstorms already with no problems. I put the nicer ones on the top row and the bottom row has many that are off the railroad and are train smoked. None of them except 1 or 2 on this fence are insulators that I consider valuable.