system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Is there some sort of YKK zipper monopoly?

99.99% of zippers I've seen in my life have the stamp YKK on them. Is there a simple reason for this?
gpt
Not a monopoly, many high-end and low-end clothing manufacturers have their own zipper production companies. YKK just makes a ton of zippers and have made them for a long time. Same thing as WD40 or GE lightbulbs, they aren't the only company who is allowed to or able to make these products, they just make the most.