Lightweight thermal efficiency. Engineered for high performance with reduced weight, the Sierra Thermal Vest offers lightweight warmth and windproof protection. Featuring Stormtech Thermal Shell insulation and a DWR water-repellent finish, this vest keeps you warm and dry while shielding you from the wind. The Thermal Shell Insulation ensures optimal core warmth, and the windproof outer shell adds an extra layer of protection against the elements. Perfect for layering, this vest is your go-to piece for warmth and performance in cold, unpredictable weather.