These clips hold my lights along my porch railing so much more tightly than nails or cup hooks. The cord doesn't slip side to side in them. They were easy to install with a drill driver and better looking than other things we've tried. Yeah, I wish they were made out of metal as well, but who could afford them? (Wouldn't they rust and get ugly?) We have the rest of our box on hand and replace them as needed through the year, not a big deal. We plan to install lights on our fence soon and will be using these. (I do wish they came in a smaller box. That's the only negative.)
I bought these clips and left them on after the season and the following season they where so brittle from the intense summer sun they all broke when I tried to reattach the lights. They only last one season and would not waist money on these clips. If you could get them in metal problem solved.