DescriptionHighlights: Temperature Boost: Adds an extra 11°F (6°C) of warmth when worn under the MT100 down jacket. Fill Power: 800 CUIN for excellent thermal insulation with minimal weight. Lightweight: Weighs approximately 7.8 oz (220 g) in size L. Compressible: Folds into its left-hand pocket with a zip featuring a double puller. Water-Repellent: Surface-treated outer fabric repels water and is PFC-free.