These web box fan holders work fine and fit standard box fans really well. They are primarily made of webbing with a thicker band at the top. The hooks are kind of small, so I replaced the with carabiners that I had laying around so that they would be easier to use and a little sturdier. Overall they're decent and work well. The stitching is just OK and not great, with some loose threads in a couple of places. It's not enough to threaten the integrity of the webbing, just something to be aware of.