PrimaLoft eco Synthetic patching reinforced Traverse Core. Featuring 2 different grades of PrimaLoft 100g/m2 and 133g/m2 – Providing extra warmth for main body while weight shaving for head and foot area. Featuring extra thick 8.9cm/3.5″ insulation layer for ultimate support and comfort. Longitudinal designed air core provides better support over traditional vertical core because of the superior numbers of individual air chambers (No Touch sound anymore). Infrared Reflective Technology added sensible warmth. Excellent companion for sleeping on snow ground for its unbeatable thickness. Works with “Dry Pump” for quick inflation.