For those spellers and readers to communicate when they don't have devices. You can toss this in a bag and go. I had a student whose communication device wasn't replaced after he broke it, for fear that he'd break another. A board like this is something cheap, easy to replace, and hard to break (when thickly laminated). Now he has something that he can use to communicate what he wants. This isn't just useful for kids - adults who can't speak can get use from this, too, in hospitals or nursing homes or outside of them. As long as you have someone else who can read and spell themselves watching what you're touching on the board (or pointing to with a head mounted laser, for those who don't have use of their arms), you can still communicate.
Looking for something with pictures? I have more free resources in my (entirely free) TPT store.