NIKE Pro Combat Hyperwarm Compression Mock Top Thermal Dri-FIT fabric - reflects warmth back to the skin while pulling away moisture keeping you warm at the same time dry. Flat-lock stitching - eliminates thick seams, for greater comfort against the skin Half-neck height - helps maintain warmth in a major heat-loss zone Compression fit - for zero distractions while you train Strategically placed flat seams - To reduced chaffing and irritation on key area.