Liner Vest - Yellow/Orange 8 oz. polyester or poly/cotton twill treated with durable water repellant plus an added wing barrier of tightly woven polyester or nylon. Insulation is 3M G200 Thinsulate or equivalent with nylon satin lining. Reflective is 3M Scotchlite Reflective 6187 or Reflexite GP350. The zipper on this vest is a #5 aluminum and works with all jackets that accept an optional liner. Sizes medium+ are ANSI Class 2, small is an ANSI Class 1 garment.