European standard EN13537, 2012: Comfort: 2.5°C (37°F) Limit: -3°C (27°F) Extreme: -20°C (-4°F) Rab® Limit: -4°C (25°F) The Women's Neutrino 400 is a light-weight, minimalist down-filled sleeping bag, designed for light-weight end uses, where warmth-to-weight is a prime concern. Pertex Quantum® outer fabric Pertex Quantum® inner fabric 800 Fill Power ethically sourced European Goose Down All down products are ethically sourced and certified to Responsible Down Standard Rab® fluorocarbon free Hydrophobic Down developed in conjunction with Nikwax® Polygiene® STAY FRESH odour control technology Mummy taper shape Proportionally assigned differential cut Internal YKK 3 coil zipped stash pocket ¾ length YKK 5 coil main zip - can be zipped to Standard bag Anti-snag zipper webbing tape Internal collar and hood drawcord Close fitting neck baffle design Trapezoidal baffle chamber design Angled foot box Dry bag compression stuff sack Cotton storage sack Temperature tested to new European standard