Shackets? What are they exactly and do you need it? It’s essentially an oversized shirt jacket –– thicker than your shirt but thinner than a coat so you can easily layer over a turtleneck or under an overcoat when it gets colder. They are basically the essential layering piece through fall and winter and are the most versatile way to elevate your style. Perfect for both men and women. I like to layer it with a sweater and leggings or a t-shirt and jeans.