Tullahoma Industries LLC is a manufacturer of Apparel for the US Military. 
Their Corporate Headquarters is located in Tullahoma, Tennessee. 
They have manufacturing facilities in Tullahoma, Tennessee, Gruetli-laager, Tennessee and Brilliant, Alabama. 
They are ISO 9001 Certified.

 

Polypropylene has the lowest thermal conductivity of any traditional apparel fiber.

Dry polypropylene fiber does not absorb moisture; it’s unique vapor transfer ability moves moisture away from skin and keeps you dry no matter what you may be doing.

Polypropylene is also color-fast, so that it will resist fading and continue to look good even in chlorinated climates.
In other words, this fabric keeps you warmer than any other currently produced apparel fabric.
If you work or play outdoors in cold weather, then polypropylene thermals are definitely for you.
They are available in black or brown and in sizes ranging from adult X-Small through adult XXX-Large.