Heat Holders Men's Original Base Layer Top is a heavy weight thermal base layer ideal for extreme cold. Matching Bottoms also available. Features: Dual Brushing: Supersoft HeatWeaver yarn is carefully brushed both inside and out to maximize warmth and softness. Perfect Stretch: Our knitting technology and attention to detail produce the perfect stretch for freedom of movement and fit. Flat Comfort Seams: Our carefully finished flat seams minimize bulk to create a comfortable non-chafe fit, perfect for layering. Moisture & Odor Management: Moisture and odor management technology helps keep you drier, fresher and more comfortable. 100% Polyester 1 Pack Machine washable at 40° Celsius (104° Fahrenheit) Imported Heat Holders Men's Original Alberto Thermal Long Sleeve Top