The Under Armour Base 3.0 Crew Top is another great addition to Under Armour's Cold Gear line up. This base layer top contains what we like to call a micro-grid fleece liner that provides superior comfort and heat regulation. The Base 3.0 layer is fitted which keeps the fabric close to the body and helps wick away moisture to keep you dry and warm. Flatlock seams are a small touch that Under Armour has added that further the user comfort in this top. The cuffs have been reinforced so they don't stretch out, provide extra warmth, and increased durability. Top to bottom the Under Armour 3.0 Base Layer crew top is the perfect base layer for any extreme cold weather application.