Specifications:

Like the fang of rock from which it derives its name, this remarkable insulating garment defies logic and reason. The jacket is lighter than a fairy's frock and hotter than a dragon's fiery breath. It is warmer than a fleece jacket, easier to compress, totally windproof and highly water-repellant. This is a must-have piece for chilly days when space is at a premium and performance is non-negotiable!