Based on out top selling n3b, the slimfit n-3b is a cold-weather parka designed for extreme weather with a contemporary streamlined fit. A revised tailored silhouette offers a comfortable fit, while the poly fill, nylon shell and longer length offers superior protection against freezing and windy conditions. The classic n-3b design was originally created to protect u.s. Air crew and ground personnel during flight operations in severe cold. It gained the common name of snorkel parka because the hood can be zipped right up leaving only a small tunnel (or snorkel) for the wearer to look out of. The slimfit is one of our best selling parkas, as it retains the protective qualities of the original alpha n-3b but offers up a more contemporary fit that is perfect for the modern look