This insulated shirt jacket is an essential in the winter months, with 650 fill power down, Heat Seal Construction to maintain warmth, and water-resistant fabric to keep rain at bay. Includes a zippered chest pocket, hand pockets with snap closures, and adjustable cuffs. This lightweight performance garment comes in multiple colors and sizes. Active Fit. To ensure the size you choose is right, utilize our sizing chart and the following measurement instructions: For the sleeves, start at the center back of your neck and measure across the shoulder and down to the sleeve. If you come up with a partial number, round up to the next even number. For the chest, measure at the fullest part of the chest, under the armpits and over the shoulder blades, keeping the tape measure firm and level.