These are mounts for the IdeaUSA Bluetooth speakers. They have an unusual shape and I wanted to mount them to the wall. Even if no one else uses them, they worked for me.

The one without the solid base is meant to be used in pairs horizontally. I mounted mine underneath a shelf with just one, successfully, but two is more stable. The other is for a vertical wall mount. It fits snugly, so there's little need for bracketed support.