An interesting thing happened to the USB touchscreen I had received...
For testing purposes, I used some handy wire and my cable trays to suspend the screen and have easy access to it. It worked well. Once I was done with testing, I decided just to leave it there for the time being. I should have known that was unwise....
I came down the next day to find the glass that had been on the front of the touchscreen was now hanging by the cable that attaches it to the monitor. If not for that cable, or if it hadn't held, then it would have smashed on the floor.
Because this had no bezel of any kind, there was nothing actually holding the glass to the front of the monitor except for sticky "weather stripping" kind of material all the way around. It was still very sticky, but apparently the combination of gravity and perhaps some cold weather down in the basement was enough to cause it to let go of the glass.
Anyway, this is not a warning of any kind about this item or the ebay seller...I'm still very pleased with both of them. It was just an interesting experience. It was a lesson, at least, that the next time I get a screen without a bezel, to make sure I put some kind of bracket on that supports the glass so it's not being held on only by the sticky stuff.