What is the point of a two-way zipper?

A two-way zipper lets you open your garment and still look cool, all without catching a chill. Berluti

Beige Metal Two-Way Separating Zipper with Gunmetal Teeth - 39 - Metal Zippers - Zippers - Notions

What is a Two-Way Zipper and What is its Purpose?

YKK #10 Aluminum Two-Way Jacket Zippers

Making a Double Head Zipper – Justine Limpus Parish's Blog

My jacket has two zippers on it. What is the purpose of the bottom zipper/ second zipper on a jacket? - Quora

Structure of a Zipper / YKK FASTENING PRODUCTS GROUP

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Wynn Hamlyn Men's Denim Zipper Jacket in White

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What is the point of a two-way zipper?

YKK Vislon Heavy Weight Two-Way Open End Zip. 61cm (24 inch).

Point Two Black Base Layer Cool-Flex™ Four-way Stretch Fabric – Point Two Air Vests

Whistles Riley Trench Coat, Neutral John Lewis Duster Coat

Ohio Travel Bag-Zippers-#10 Vislon, Black, 30 YKK Separating Two-Way Jacket Zipper, Plastic, #10VTW-30-BLK-$8.10

What is the purpose of a double zipper? - Quora