What's the name of this fastener?

On one end is a hole for a screw to go in. It makes a loop (half-circle) and has a hole on the other end for a screw. I want to attach a metal art insert into a niche in my living room, but the art doesn't have any holes in it, so instead I want to attach it with a smaller piece of metal (the fastener) that goes around an edge and attaches to the wall on either side. I hope this makes sense. Thank you.