Engineered to be the lightest and warmest synthetic bag on the market laminatrade construction welds the thermalqreg insulation to the shell and lining eliminating the cold spots caused by traditional stitching by mapping different insulation weights throughout the top of the bag we are able to concentrate warmth where you need it most ndash around your core and feet thermal efficiency is optimised by a performance mummy cut face gasket and single center half zip materials fabric b