SSG® 10 BELOW WATERPROOF - Style 6400 Proven waterproof protection. Knitted cuff and stratch back Thinsulate is the warmest thin glove insulation available, even in damp conditions. It provides about 1 1/2 times the warmth of down, and about twice the warmth of other high loft insulation materials. Polar fleece is a soft napped insulating synthetic wool fabric that is comfortable to wear, very warm and provide a lightweight warmth. Good alternative for those that are allergic of sensitive to wool.