Carhartt 104050 is an updated version of the classic J130 Active Jac, one of Carhartt's most popular insulated jackets. The shell is made from Carhartt's well-known heavyweight washed duck at 12 oz (407 g/m²) in 100% ring-spun cotton, and the jacket is insulated with 80g 3M Thinsulate – a lightweight, high-performance insulation that provides warmth without added bulk. The jacket is rated Warmth Level 3 (warmest) and is well suited to extremely cold conditions.

The interior is lined with quilted nylon, making the jacket easy to put on and take off. It features a full-length front zip, an attached hood with drawcord and cord lock, and internal rib-knit storm cuffs that keep out the cold. Articulated elbows allow freedom of movement, and Cordura-reinforced cuff edges withstand extra wear.

Two lined front pockets (one with a pen loop) and two internal pockets provide ample storage. Triple-stitched main seams ensure the jacket holds up to heavy use year after year.