Product details:

Featuring ColdGear Reactor and Storm technology, the Under Armor ColdGear Reactor Run Undershirt is the perfect running companion in colder conditions. Water-resistant and quickly adapting to your temperature as you train by intelligently retaining and releasing heat so you stay comfortable, focused and free from distraction. Crafted in a fitted, next to the skin fit with stretch-woven inserts to enhance mobility, while an invisible side zipper construction allows for an easy on/off. An adjustable knit collar can be worn up for full-face coverage on the coldest days and reflective logos keep you visible in low lighting conditions. Finally, a secure zipper back pocket provides safe and secure storage for your keys or cards.