Mountain Equipment Helium 250 Women's Sleeping Bag

Weighing less than a standard water bottle and compressing to a similarly compact size, this sleeping bag is an ideal choice for the dedicated warm-weather adventurer seeking to reduce pack weight without sacrificing comfort.

Crafted with 261g of minimum 700-fill power duck down that meets the DOWN CODEX® ethical standard, and encased in a high-performance Helium 20D outer fabric made entirely from recycled materials, the Helium 250 sleeping bag is both lightweight and highly compressible. It offers exceptional warmth and efficiency for backpackers and cycle tourers who value compact gear for their warm-weather adventures.

The body features a slant-baffle construction, which enhances insulation, boosts compressibility, and effectively prevents the down from shifting—ensuring consistent warmth and eliminating cold spots. At the foot end, a Trapezium 4 System employs four baffles to concentrate heat where it is most needed, while the hood benefits from a five-baffle design to maximise comfort and maintain precise down placement.

Inside, the sleeping bag is lined with a soft and durable Supersoft™ 20D fabric, made from 100% recycled fibres and treated with a PFAS-free durable water repellent (DWR). A full-length Gemini™ zip baffle significantly reduces heat loss along the zip line and includes a stiffener to prevent snagging. The Lode Lock™ magnetic closure system, combined with collar drawcords, offers simple, intuitive use—particularly useful during the night.

The Helium range features the Alpine 2.0 fit, a technical yet comfortable design that maximises thermal performance while keeping weight to a minimum. With a Good Night’s Sleep Temperature rating of 1°C (34°F), the Helium 250 is a top-tier choice for those embarking on warmer weather camping and backpacking trips.

Features

Insulation

• The insulation is optimised in each baffle to provide the best possible warmth-to-weight balance.
• The Regular version contains 242g of 90/10 duck down with a minimum 700 fill power.
• The Long version holds 256g of 90/10 duck down with a minimum 700 fill power.
• All down is responsibly sourced through the DOWN CODEX® and RDS 3.0 standards.
• Each sleeping bag includes a unique DOWN CODEX® code to provide transparency about sourcing and fill quality.

Materials

• Recycled HELIUM™ 20D: A 20-denier fabric weighing 38gsm, designed to be lightweight yet durable, offering excellent compressibility and protection against wind and heat loss, finished with a PFAS-free DWR.
• Supersoft™ Lining: A 38gsm recycled 20D downproof nylon that is breathable, soft against the skin, and treated with a PFAS-free DWR for enhanced durability and comfort.

Patterning & Design

• Built for long-term durability and high-level technical performance.
• The Women's Alpine Fit features a refined taper with a zoned EXL® system that boosts thermal efficiency while keeping bulk to a minimum.
• Slanted box-wall baffles reduce weight and maximise thermal retention.
• The fill is strategically distributed, with increased density in high-compression zones like the underside, hood, and foot box to prevent down displacement and improve warmth.

Foot Box

• Trapezium 4 System: Utilises a four-baffle design to maintain loft and warmth around the feet while avoiding compression.

Hood

• Features a five-baffle layout to maintain down stability, reduce weight, and improve insulation.
• Designed to be roomy yet thermally efficient, with dual drawcords to limit heat escape.

Zip Baffles & Collars

• Gemini™ Baffle System: Provides a lightweight, low-bulk solution to heat loss around the zip, while still offering full protection.
• Lode Lock™ System: Combines magnetic and mechanical fastening for secure closure and one-handed use.
• Includes an integrated, adjustable down-filled neck collar to further retain body warmth.

Additional Features

• Comes with a waterproof roll-top stuff sack to save space and protect contents from moisture.
• Includes a storage cube designed to preserve the down's loft, ensuring optimal long-term performance—ideal for use when storing the bag at home.
  
  

Specifications

Technology

	DOWN CODEX® The DOWN CODEX® is our multi-award-winning certification scheme that considers the environmental, ethical and animal welfare matters relating to our down supply chains. Underpinned by the Responsible Down Standard, it is based on independent audits and a rigorous paper trail.
	Down 700 Down is the finest insulator. Manmade insulations cannot match its warmth-to-weight ratio, compressibility, long lifespan, and softness. Duck Down is great for insulated clothing and equipment for all but the most serious expeditions.
	Helium Helium fabrics are exceptionally light, compressible and soft. Their densely woven construction ensures the highest levels of down-proofing and wind resistance.

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