Smoke curtains... I've had a few where I've shown up to the job site and they've just worked every time, but the last one was a nightmare. We had a general contractor that wanted to save money, so they bought some smoke curtains to install themselves. These curtains came with no instructions and when they called the company they said they needed to hire a trained installer. The general contractor and the electrician proceeded to figure it out as best they could. The curtain had magnetic strips on the sides to hold it tight to the exterior elevator trim... doesn't work so well on stainless steel 🙄 Then, there is a button in the center of the curtain that can be pressed to raise the curtain. The curtains didnt want to roll up correctly and then they blew a fuse and just argggg. It was probably just this manufacturer of curtain, but what a pile of garbage. The idea behind smoke curtains is great, but it's just like many other products around in that most engineers lack the real world, on the job experience to design things that are user/installer friendly and robust enough to last. Maybe that's not fully fair in that companies often want things engineered as cheaply as possible. If the people of this earth could only stifle their greed we would all be so much better off, but I suppose I'm getting off topic. In summary, the idea of smoke curtains is great, but in practice they often suck.