Mountain Equipment Helium 600 Women's Sleeping Bag

The Helium 600 is filled with 620g of minimum 700-fill power DOWN CODEX-approved duck down and uses 100% recycled Helium 20D outer fabric. This makes it incredibly warm, lightweight, and easy to compress for packing. It's a durable and versatile for early spring, autumn, or colder northern climates. 

Slant-baffle construction throughout the body ensures warmth, improves packability, and prevents the down from shifting, eliminating cold spots. A four-baffle system at the foot keeps your feet warm, while the five-baffle hood keeps down in place for maximum comfort.

The inside is lined with 100% recycled Supersoft 20D fabric with Fluorocarbon-free DWR, offering breathability and durability. A full-length Gemini™ zip baffle prevents heat loss, and the stiffened design stops the zip from snagging. The low-profile magnetic Lode Lock™ closure and easy-to-use collar drawcords add convenience, even in the dark.

With a technical Alpine 2.0 fit, this bag optimizes warmth while keeping weight down. Rated with a Good Night’s Sleep Temperature of -10°C (14°F), the Helium 600 provides reliable insulation in cooler conditions and at higher altitudes.

Features

Insulation

• Every baffle has been carefully optimised to deliver the highest possible warmth-to-weight efficiency.
• Regular version is filled with 547g of 90/10 Duck Down boasting a fill power of 700+.
• Long version includes 576g of 90/10 Duck Down with a 700+ fill power rating.
• All down used is responsibly sourced in accordance with DOWN CODEX© and the RDS 3.0 standard. More details on DOWN CODEX are available for those interested.
• Each sleeping bag is tagged with a unique DOWN CODEX© code, allowing full traceability of the down’s origin and fill quality.

Materials

• Recycled HELIUM™ 20D is used—a lightweight (38gsm), 20-denier recycled fabric that offers a fine balance of resilience, compressibility, and elemental resistance. Its dense weave reduces wind penetration and heat loss, complemented by a PFAS-free durable water repellent finish.
• Supersoft™ Lining comprises 38gsm 20D recycled downproof nylon, engineered to be breathable, robust, and exceptionally comfortable against the skin. This too features a PFAS-free DWR coating.

Patterning & Design

• The construction is engineered to withstand extended use while delivering high-level performance.
• The Women’s Alpine Fit adopts a sculpted, tapered profile, enhanced with a zoned EXL® system that boosts thermal retention without adding unnecessary weight.
• Slanted box-wall baffles are used to lower structural weight while improving insulation effectiveness.
• Insulation is strategically placed with denser fill in critical zones—such as the base, hood, and foot box—to curb down movement and ensure consistent warmth.

Foot Box

• The Trapezium 4 System features a four-baffle layout that elevates warmth and eliminates cold spots by reducing compression around the feet.

Hood

• A five-baffle construction ensures precise down placement, reduced weight, and excellent heat retention.
• Designed to feel both spacious and secure, it includes dual tether drawcords to seal in warmth and block out the cold.

Zip Baffles & Collars

• The Gemini™ Baffle System offers a lightweight, low-profile solution that limits heat escape while maintaining full functionality.
• The Lode Lock™ System employs a secure magnetic fastener with a mechanical lock, allowing a fast and intuitive one-handed release.
• A built-in, adjustable neck collar filled with down adds an extra buffer of warmth around the upper body.

Additional Features

• A waterproof roll-top stuff sack is included to maximise packing efficiency while keeping contents dry.
• A dedicated storage cube is provided to help preserve the loft of the down, supporting better long-term performance and ideal for use at home.

Specifications

Technology

	Down Cycle The recycled Down Mountain Equipment comes entirely from post-consumer goods—unwanted clothing and bedding collected by waste recycling companies.
	A Good Night's Sleep Guaranteed We are so confident that our sleeping bags will keep you warm and comfortable that, in addition to the EN13537/ISO23537 laboratory ratings we quote, every Mountain Equipment sleeping bag comes with a separate ‘A Good Night’s Sleep Guaranteed’ temperature rating.
	Down 700 Down is the finest insulator. Manmade insulations cannot match its warmth-to-weight ratio, compressibility, long lifespan, and softness. Duck Down is a great choice 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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