ColdGear® Infrared technology holds in body heat, without adding weight or bulk. It's a special, soft print on the inside and it keeps you warmer, longer, so you can work out in the bitter cold. 4-way stretch material moves better in every direction DNA Dual-layer fabric with an ultra-warm, brushed interior & a smooth, fast-drying exterior ColdGear® Infrared technology uses a soft, thermo-conductive coating to absorb & retain your body heat Material wicks sweat & dries really fast 4-way stretch material moves better in every direction Reflective details for low-light runs 87% Polyester, 13% Elastane