The dollar one I bought actually was in a case with three different interchangeable heads. It was very cheaply made but actually worked just fine. It took A-76 batteries.
I doubt it could have done any damage at all except I did tell him not to point it at anyone’s eyes. It was fun to play with.
I played with the one I bought a few times then it sat on the shelf.
It’s on Ebay now. I’m looking at clearing excess stuff that’s piled up here over the years.
My mastiff and a temporary cat loved chasing that little red laser dot.