You use it with yarn to make squares that you then sew together with yarn. I got it from a thrift store that we used to go to a lot when I was a kid. I've probably had this loom since I was 12 years old! I used it to make a scarf and a wall hanging, as well as a carpet and a blanket for a bed for my sister's dollhouse. I used it to make other things as well, but those are the main projects I remembered. It is called the Wonder Weave, manufactured by Karbercraft Co back in 1964. I still have the project book and the instructions that go with it.
I don't recall if I have any pictures of the projects I made with it, but if I come across any I'll post them. Who knows, maybe I'll start using it again!