X-Small(5/7); Small(6/8); Medium(8/10); Large(12/14); X-Large(16/18); The Kids Pepper Skins thermal underwear Top, by Hot Chillys, is made of 100% micro denier polyester yarns seasoned to transport moisture and reduce odor retention. The rugged 8 oz. jersey construction is lightly sanded for added warmth and exceptional feel. This midweight base layer breathes easily while providing exceptional moisture management for all cool weather activities. The construction features quality five thread flat seam construction for superior seam strength, brushed waist band for softness next to your skin, and a relaxed fit for easy movement. Washer and dryer safe. Added washing increases loft and softness. Expect light pilling, does not effect performance of product.