You can wear it 24/7 without feeling sweaty and sleep comfortably wearing it. 100% cotton (exclusive of trimmings) Excellent Quality! Heavyweight ring-spun pre-shrunk 240 gsm and the naturally breathable fabric,let the cold winds blow!! natural cotton provides all the toasty warmth that needed for four season warmth , comes in five fab shades Long John and Y Front Brief styles. men’s underwear lends a helping hand to see you through the chilly winter months. The Modern Classic Long Johns use a soft high quality cotton These Modern Classic Long Johns are available in Black, White, Navy,Charcoal, Light Grey and Cream *Soft Rib Knitted Cuffs *100% Comfort Soft Cotton *Pure Cotton with Highest Wearing Comfort * Y Front Brief styles.