Under Armour Extreme Celsius Half Zip Fleece Top ColdGear Fabrication - Provides enhanced warmth and superior comfort. On-Demand Ventilation -  zip allows ventilation control when the weather is getting hot. Strategic vent zones  Allowing the body to dump heat whilst keeping you dry. Under Armour Branding on chest and back of neck. 86% Polyester, 14% Elastane  Both lightweight materials.