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Images: Mountain Equipment and its retailers. Used for product identification.

Mountain Equipment

Mountain Equipment Helium 400

The 3-season benchmark: 0 °C comfort at 820 g, widely stocked and often discounted.

Weight
820 g
Comfort
0 °Climit -6 °C
Packed
24 × 21 × 20 cm

Best price found

£240

at Trekitt · In stock · RRP £300.00

View Deal
  • Cotswold OutdoorOut of stock at check£245.95View Deal
  • Mountain EquipmentIn stock£300View Deal

Prices checked 31 October 2026. We may earn a commission on these links.

  • 700 FP down
  • RDS down
  • Recycled fabrics
  • Box-wall baffles

Specifications

Weight
820 g (870 g long)
Packed size
24 × 21 × 20 cm
Comfort
Comfort 0 °C / limit -6 °C
Fill
700 FP duck down, 403 g fill
Shell & construction
Recycled HELIUM 20D nylon with PFAS-free DWR; Slanted box-wall baffles with zoned EXL fill…
Rating Standard
ISO 23537 rating
Fill Note
700+ fill power 90/10 duck down, DOWN CODEX traceable, RDS 3.0 certified. No…
Zip
140 cm zip, left or right, with full-length Gemini zip baffle
Manufacturer page →

Pros & cons

  • Good balance of warmth, weight and value
  • Magnetic Lode Lock hood/collar closure works one-handed and with gloves
  • Smooth, well-baffled side zip and box-wall construction with no reported cold spots
  • Slim alpine fit may not suit larger builds
  • Duck rather than goose down, and no hydrophobic treatment

Sources for this product

  1. 1Mountain Equipment product page
  2. 2Trekitt listing
  3. 3Cotswold Outdoor listing
  4. 4Outdoors Magic review, 26 May 2017
  5. 5Outdoors Magic review, 11 May 2017

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