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A 3 to 4 season ultralight down sleeping bag designed for minimum weight (only 1lb. 13.9oz!) & maximum versatility, the Helium 450 has proven popular with hikers in a range of climates from coastal walks to sub alpine elevations.
Mont Adventure Equipment says:
A 3 to 4 season ultralight sleeping bag designed for minimum weight (only 1lb. 13.9oz!) & maximum versatility, the Helium 450 has proven popular with hikers in a range of climates from coastal walks to sub alpine elevations. The 450 allows temperature regulation with dual zippers & offers incredible warmth-to-weight thanks to 800+ loft down. Maximise your pack space with a compact, lightweight and versatile Helium 450 sleeping bag.
Ultralight shell fabric and high-loft RDS down fill on the Helium bags mean higher performance for less weight. Durable 10 by 10 denier, 520 thread count Nylon weighing only 26g/m2 with a hot-rolled-cire treatment to prevent down leakage and increase durability. Premium 800+ loft RDS white down fill with DWR Loft treatment adds greater resilience, higher loft and better warmth in damp conditions.
Our Verdict
Mont Adventure Equipment is an Australian company known for making high-performance gear for demanding alpine conditions, with a focus on low weight, precise design, and reliable materials. The Helium 450 LHZ Down Sleeping Bag is a clear example of that design philosophy.
Weighing 829g, this three-season bag offers reliable warmth with an updated 800+ loft down fill, treated to maintain loft in damp conditions. The cut strikes a good balance between room to move and thermal efficiency, with a generous footbox and well-contoured hood. Vertical and radial baffles help stabilise down distribution across the torso, and the box-wall construction limits cold spots effectively.
The bag compresses well to around 15 × 31 cm and lofts quickly after unpacking. Moisture resistance is strong thanks to hydrophobic thread and treated down, and breathability holds up in variable conditions. Construction is clean, with tuck-stitched seams and a durable shell for its weight class. The dual zip setup offers practical venting, though the side zip can occasionally snag under load.
For colder multi-day trips where space and weight matter, the Helium 450 is a well-executed solution with a reliable warmth-to-weight ratio and excellent packability.
- Reviewed by Ultralight Outdoor Gear
Features
- Tapered rectangular shape with a wide foot section for room to move
- Radial Arc Baffle System on horizontal baffles maximises loft height & warmth
- Vertical baffles on torso maintain optimal down distribution
- Differential cut reduces compression & cold spots
- Box walled baffles for warmth & weight efficiency
- Large down-filled 3D draft tube along zip retains heatÂ
- Contoured hood keeps down evenly distributed around head
- Laminated 210 denier Nylon anti-snag shield along zips
- Sewn with hydrophobic Epic thread to prevent moisture from wicking along seams and inside the shell
- Tuck stitched for seam strength & greater water resistance
- Full length YKK side zip with dual sliders & foot zip
- Includes ultralight siliconised-Nylon Z-Force Mechanical Advantage Compression Stuff Sack & 50L / 3,051cu. inpolyester storage sack with printed care & washing instructions
Specifications
- Regular Weight: 829g
- Long Weight: 966g
- Compression Sack Weighs: 97g
- Cold Sleeper: 30°F / -1°C
- Warm Sleeper: 19°F / -7°C
- Season Rating: 3 Season
- Packed size: 5.9x12.2 inches (15x31cm)
Material & Construction
- Shell fabric 520 thread count, 10 by 10 denier ultralight Nylon (26g/m2)
- Lining fabric 520 thread count, 10 by 10 denier ultralight Nylon (26g/m2)
- Down rating 800+ loft premium RDS white duck down
- Down treatment Water resistant DWR Loft treatment
- Zip side: Right Regular, Left Large
- Zip configuration Side & Foot zips. YKK brand zips, dual sliders on side zip
- Colour Orange/Black
