New POLARTEC Power Dry ECWCS Cold Weather Undershirt - Small/Short.
Polartec Power Dry material
Constructed from FAMOUS POLARTEC POWER DRY MATERIAL. This is a level 1, "silk weight", thermal base layer that is used by the U.S. Military. 
An undergarment, usually long-sleeved, primarily designed for protection at mean monthly temperatures of plus 14 degrees Fahrenheit (minus 10 degrees Celsius) to plus 68 degrees Fahrenheit (plus 20 degrees Celsius). Excludes undershirt, man's; undershirt, extreme cold weather; undershirt, moisture wicking and undershirt, woman's.
WEIGHT ONLY 7 OZ 
The base layer is moisture wicking, breathable and lightweight. It helps keep you warm and dry while moving around and sitting. The level 1 base layer is very durable and can be worn like compression clothing with it tight against your skin or more loosely depending on your preference. The Power Dry design allows moisture to escape and at the same time has water-resistant properties.

NSN 8415-01-547-6680