A durable surplex undergarment, made of a 3M thinsulate material, this undergarments insulation traps and holds body heat with three layers of warmth, repellent, and safety. Using an innovative water repellent, breathable material, the 100 Military Tri-Lam Undergarment dries quickly, has a super water and stain repellent finish, and is effective when damp and after repeated washing. This undergarment is available in black and although it lacks the bulk of down insulated garments, it is nearly 1 ½ times as warm.