BlackHawk Products Group introduced the Warrior Wear Shell Jak a couple of years back. This jacket is designed to work as either a standalone piece or layered with the company's Operations or Training Jacket, depending on weather conditions. The Shell Jak is sized to fit with or without the other jackets. Warrior Wear's Shell Jak is built to keep you dry in the roughest nor'easter. The outer zippers are waterproof, the seams are sealed, the hood and jacket have drawstrings to keep in your body heat and the wet out, and the collar is fleece-lined for comfort. To help keep you from getting wet from sweat, there are large armpit zippers which are also waterproof.