The Finnfill Heavy sub-jacket is made of elastic and waterproof material that provides excellent thermal insulation. The Heavy model is designed to be worn even in extremely cold conditions. It is made of four layers;
- insulating: made of Finnfill fibres
- waterproof and breathable X- Tex membrane
- surface: elastic and smooth Tricot fabric
- inner: fleece
Finnfill insulation is the most distinctive and unique feature of X-Tex sub-blends. The material does not lose its insulating properties even after repeated washing and retains them even when the suit is completely wet. The suit has ventilation holes on the left sleeve and underarm, a double zip fastening, a zipped chest pocket and large pockets on the thighs.