SmartWool Phd Wind Zip Running Top - AW15 Merino/polyester blend - Ensures fabric moves moisture, dries quickly, and maintains its shape in high-sweat activities in colder weather. Form Fit - Allow for multi-directional movements. Minimal Merrow seam construction - Provides superior durability and is soft against skin. 13.8" (35 cm) center front zipper with chin guard - Protection against the elements. Windproof front Panel - This catches the cold air in its layered branching thus adverting it away from the body.