Junk or not?
"Inexpensive"* (to most) no name from Amazon.
Frame and forks are a full 7/16 inch/11mm thick, and have no flex, so I'm not worried about it breaking when at my (pathetic) full draw.
The bands look to be 1mm, when held against my vintage style wood ruler. (I don't have anything more accurate.)
(*"Inexpensive" and "expensive" is income dependent, of course. For me, it was "relatively expensive", at around $18, (plus tax and free shipping) or just under 50% of my monthly income, after paying rent and room n' board. (Assisted Living facility))