What is this document fastener called?

Factual Questions
1

I have been looking for some of these SOM1-01 document fasteners, which we can see in the photo, on the left side of the document. I was only wanting one or two, in a cheapie little notebook like, so I thought I could go to Wally World and get one. No luck, so, I thought I would go online and see how much they were, and I realized that I had no idea what they were called.
Can anybody tell me?

Thanks
hh

2

I’ve always heard them called “Acco fasteners,” and the ones on my desk right now are indeed marked “ACCO”.

3

They’re commonly called ACCOs, but the generic name is “prong fastener.”

4

Thanks, y’all!

hh