You probably use a zipper on most days without thinking twice about it… until one gets stuck and ruins your morning. This video takes that tiny everyday hero and blows it up, literally, by building a giant working zipper to show what’s actually happening inside. And it turns out, this simple little mechanism is a masterpiece of engineering. From its early designs to the genius Y-shaped slider that makes everything “just work,” there’s way more going on than meets the eye.

Also: yes, there’s a reason every zipper says YKK, and yes, you’ve been using them way more than you think.

It’s one of those “how did I never notice this?” rabbit holes, and now you’ll never look at your jacket the same way again.