Features:

• Waterproof Body X Top, Men's Undergarment:
• High Thermal Insulation w/o Increasing Weight
• Made of Hollow Fiber Polyester
• Inspired by Structure of Polar Bear Fur
• Insulates Far Better Than Regular Fiber

Details: To achieve high thermal insulation without increasing weight, BODY X and BODY 2X are made of a hollow fiber polyester. Inspired by the structure of the fur of a polar bear who lives under extreme environmental conditions. It insulates far better than a regular fiber because it is hollow and filled with air.

Brand: waterproof