The Under Armour® Base™ 4.0 Crewneck is lightweight, breathable warmth with a polyester/elastane 4-way stretch fabric that moves with you through your run, hike, or outdoor workout. This Under Armour long-sleeve layering t-shirt is made of a thermal grid fabric that traps heat in tiny pockets for lasting warmth and protection. Moisture wicking and antimicrobial technologies help the fabric dry quickly and block bacteria growth. Raglan sleeves with thumbholes are ideal for active, outdoor wear. The Under Armour Base 4.0 Crewneck for ladies is sleek and fitted without the squeeze of compression, and makes a great base layer for extreme cold. Imported. Manufacturer style #: 1280942.