I work five nights a week and keep night hours on my days off, so having a pitch-black room is essential to my health and happiness. After reading some reviews I settled on the Indow sleep panels. My house was built in 1901. I have two bedroom windows that are about 6' tall and 3' wide. From the time I got in touch with Indow, through the measuring process, through the production and delivery of my inserts I felt like they were supportive. Reading the installation guide before their arrival was essential in preparing me for the process. I knew I'd need to install window brackets with a power drill and that unboxing the inserts might be a bit of a chore. This made the installation process smooth which I greatly appreciated. The inserts arrived a few hours after I'd worked through the night, so I was ready to get them installed in short order and get to sleep at a reasonable hour that day. As to their efficacy, the panels block all the light. The sound dampening isn't powerful, but I knew that going in as well. The inserts need to sit 4" from the glass for the full dampening effect and mine can only sit at about 2". There is a dampening effect, just not at the 50% noise reduction that they're capable of. The delivery service that shipped to my house didn't call to schedule the delivery as the instructions said they would. That's the only thing that didn't go according to plan, but I was home so it worked out. Other than that one thing, the panels perform as I hoped they would. I'm grateful for my dark room and my consistent deep sleep because of them. I would work with Indow again in the future.