Athletic Works Boys' Thermal Base Layer Long Sleeve are designed with anti-odour and moisture-wicking properties to keep kids warm and comfortable throughout cold days. This light and soft base layer is made of highly breathable fabric and brushed on the inside making it the perfect layering piece for outdoor activities. A more fitted design prevents adding extra bulk under clothes. Sewn with flat seams and a no tag design which is great for kids sensitive skin and won’t chafe or bunch. Base layer bottom is also available for a matching set. Athletic Works gives you consistent comfort, durability and value for your everyday wardrobe essentials. 90% Polyester, 10% Spandex.