The one I use at my gym seems like a basic leather belt with a chain on it. It gets the job done. I'd say any product from a reputable brand would be okay.
A funny story about dipping belts... I was doing dips with two 45 plates one time and afterwards a guy complemented me on my insane thigh strength. It didn't take him long to figure out I had a belt on, but it was funny because for a few seconds there, he'd thought I was holding those two plates between my thighs. Haha!