"Under Armour Metal" refers primarily to the material used in ColdGear products. It's a thin, stretchy material that balances breathability and insulation, making it a high-performance base layer. This material is used in areas prone to sweating, such as the underarms and back, to help regulate body temperature even during intense winter workouts, supporting comfortable performance. - Brand: Under Armour - Color: Gray - Design: Undershirt - Logo: Under Armour logo - Features: Side mesh panels - Material: Stretch material Thank you for viewing. I will ship it compactly.