Briefs from Calvin Klein Jeans. Choose breathable comfort and a sporty look with our signature Modern Cotton underwear and loungewear collection. Highlights. Regenerative cotton elastane blend. Normal waist. Calvin Klein signature elastic waistband. Material Composition: Main composition: regenerative cotton (95%), elastane (5%) Sustainability Certification. RegenAgri Care instruction: Machine Washable at 30°C, gentle cycle. Low heat iron. Article Code: G80G8007110TV.