This does not seem to be designed with standard pegboard in mind. I was a little “cut happy” and cut these out without really inspecting them only to discover it’s not for standard pegboard.
It’s possible this is for Ikea Skadis board, but I am not sure - I don’t have any to verify.
I agree - no way are rectangular pegs fitting into round holes. You can click the “report this design” link in the catalog to provide feedback to the Catalog team (GF staff don’t monitor the forum).
I have a pegboard hanger “kit” which includes molded plastic pieces with rectangular hooks. They just have to be the right size to fit thru the 1/4" holes (which they were)…
Ok, after even more research, I think I’ve determined that these are Ikea Skadis hooks, rather than the 1/4" / 1" spacing ones I’ve got in my shop. Here’s an example with precisely the same configuration: PrusaPrinters