Summer down1 / 11
Images: Mountain Equipment and its retailers. Used for product identification.
Mountain Equipment
Mountain Equipment Helium 250
660 g of summer warmth with a +7 °C comfort rating, often discounted at Cotswold.
- Weight
- 660 g
- Comfort
- +7 °Climit +2 °C
- Packed
- 19 × 17 × 15 cm
Best price found
£199.95
at Cotswold Outdoor · In stock
- Ultralight Outdoor GearIn stock · RRP £249.99£209.99View Deal
- Ellis BrighamIn stock£250View Deal
- Mountain EquipmentIn stock£250View Deal
Prices checked 31 October 2026. We may earn a commission on these links.
- 700 FP down
- RDS down
- Recycled fabrics
- Gemini zip baffle
- Box-wall baffles
Specifications
- Weight
- 660 g
- Packed size
- 19 × 17 × 15 cm
- Comfort
- Comfort +7 °C / limit +2 °C
- Fill
- 700 FP down, 261 g fill
- Shell & construction
- Outer: recycled Helium 20D, 38 gsm, PFAS-free DWR. Lining…; Slanted box-wall baffles
- Rating Standard
- ISO 23537 rating
- Fill Note
- Regular 261 g, Long 273 g. RDS 3.0 certified and traceable through DOWN CODEX.…
- Season
- 2-season
- Zip
- 140 cm zip with full-length Gemini zip baffle
Pros & cons
- Trek & Mountain called it a 'near flawless lightweight, well-priced all-round bag'
- 'Lofts up really nicely' and was 'decently warm down to around freezing point'
- Very light and packable for its warmth
- Advnture found it 'too light and not insulated enough' for anything but fair weather
- Trek & Mountain's tester was 'slightly skeptical about the temperature rating'
More down bags
Full comparison →
11 photosBest valueAlpkit
Alpkit PipeDream 400
Hydrophobic 750 FP RDS down with a -4 °C comfort rating for under £300, direct from Alpkit.
- Weight
- 770 g
- Comfort
- -4.2 °Climit -10.8 °C
- Packed
- 25 × 18 cm
- 750 FP down
- Hydrophobic down
- RDS down
- 160 cm zip
- Draught collar
Full specs, 1 retailer →View DealFrom
£274.99
at Alpkit
11 photosBest all-rounderMountain 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
- 700 FP down
- RDS down
- Recycled fabrics
- Box-wall baffles
Full specs, 3 retailers →View DealFrom
£240
at Trekitt
Lightest for warmthCumulus
Cumulus Panyam 450
Polish-made 850 FP goose-down bag that undercuts the big brands; ships from Poland.
- Weight
- 810 g
- Comfort
- 0 °Cbrand's own figure
- Packed
- 26 × 18 cm, 6 L
- 850 FP down
- Box-wall baffles
- Two-way zip
Full specs, 1 retailer →View DealFrom
£289
at Cumulus
