What is the point of a two-way zipper?

Two-Way Zippers: Yay or Nay - YLF

Why do some coats have a zipper and buttons on them? - Quora

Editorial

Separating outerwear zipper is perfect for vests It is perfect for jackets Made in United States

YKK Vislon 2-Way Separating Zipper, 30, Black

We think this reversible vest with a two way zipper is going to be a big hit for this fall 🍂 great price point at $120 and great…

Why do some jackets have two zippers? - Quora

double zip jacket

What is the purpose of a double zipper? - Quora

#5 Molded Black Vislon YKK Jacket Reversible 2-Way Separating Zipper. Perfect For Parkas, Ski Jackets, Coats, Vests, Outdoor Wear, Casual Wear,

#5 Molded Black Vislon YKK Jacket Reversible 2-Way Separating Zipper - Made in The United States (1 Zipper Per Pack) (29 Inches)

Zipper - Wikipedia