The Naturehike Penguin Cotton Sleeping Bag is engineered for serious cold-weather camping. Available in two fill densities — P300 (300g/m²) and P400 (400g/m²) — it uses a down-cotton mixture fill (cotton base, down top layer) that delivers exceptional warmth-to-weight performance. The polyester pongee outer and washed cotton lining create a durable, skin-friendly shell that holds up across seasons. Rated temperatures are precise and tested: P300 is comfortable to 6°C, with a limit of 1°C and extreme rating of -13°C. P400 pushes further — comfortable to 1°C, limit -4°C, extreme -18°C. At (190+30) × 80 cm, the extended footbox accommodates adults up to 1.8 m with room to spare. Specifications Specification P300 P400 Brand / Model Naturehike NH21MSD03 (Penguin) Style Mummy Filling Down-Cotton Mixture (Cotton Base + Down Top) Outer Fabric Polyester Pongee (Nylon) Lining Washed Cotton Fill Density 300g/m² 400g/m² Weight 1.5 kg 1.85 kg Packed Size Ø25 × 36 cm Ø28 × 38 cm Comfort Temp 6°C / 42.8°F 1°C / 33.8°F Limit Temp 1°C / 33.8°F -4°C / 24.8°F Extreme Temp -13°C / 8.6°F -18°C / -0.4°F Unfolded Size (190+30) × 80 cm Splicing Yes – single or double configuration Applicable Users Adults (up to 1.8 m) Color Grey Why Choose the Naturehike Penguin? Precise Temperature Ratings: Comfort, limit, and extreme temperatures are clearly specified for both P300 and P400 — choose the right bag for your conditions with confidence. Down-Cotton Mixture Fill: Combines the loft and warmth of down with the moisture resilience of cotton — better performance than pure cotton fill in cold, damp conditions. Washed Cotton Lining: Soft, breathable, and skin-friendly — the kind of lining that makes cold nights ly comfortable. Extended Footbox: The (190+30) cm design adds 30 cm of extra room at the foot — no more cramped toes on cold nights. Naturehike Quality: Backed by a globally recognized outdoor brand with a reputation for reliable, well-engineered gear. I For Autumn and winter camping trips Cold-weather backpacking and trekking Sub-zero expeditions (P400) Campers who want precise, tested temperature ratings Adults who need a reliable, well-insulated mummy bag In the Box 1 × Naturehike Penguin Cotton Sleeping Bag (P300 or P400 as selected) 1 × Compression carry bag