Senchi Designs Alpha 90 Crewneck with half zipSenchi Designs Alpha 90 Crewneck is an incredibly lightweight half zip crewneck. The half zip is awesome when outdoors because it allows for a wide range of temperature management. Minimal design, easy layering, extremely versatile. Made from Polartec Alpha Direct 90, this crewneck is designed for maximum breathability and warmth retention. It's super breathable and surprisingly warm wearing under some wind blocking layer. If it's worn as an outer