The Platinum(TM) layer because you're at your best when nature does its worst. The Platinum Crew from Coldpruf features a dual layer system which provides maximum protection in the most extreme cold. Inside layer is 100% Polyester while the outside layer is a 70% Polyester / 30% Merino Wool Thermal blend. Rated for very to extreme cold. Allows for Medium to high activity. Pairs with the Platinum Crew. | Coldpruf Platinum Thermal Pant in Black | Size Small