Helium 300 4 to -1°C Down Sleeping Bag

Ultralight but durable 10 by 10 denier, 520 thread count Nylon weighing only 26g/m². Finished with a hot-rolled cire treatment to prevent down leakage and increase durability.

Differential cut is the term used to describe the difference in circumference between the inner and outer shells. The differential cut prevents down compression and cold spots by reducing the chance of the inner shell compressing against the outer shell.

For a truly effective differential cut there should be a considerable difference in the circumference of the inner and outer shells.

The Radial Arc Baffle System is a significant design innovation that improves the thermal efficiency of a Mont Sleeping Bag.

Radial Arc Baffles curve naturally around your body rather than bending around your body. When a down baffle (chamber) is bent or distorted, ripples in the fabric occur which will compress down and create cold spots. The Radial Arc Baffle System reduces bending and distortion and increases loft and warmth.

Tuck stitching is a construction method that conceals the stitch inside the sleeping bag thereby protecting it from abrasion and snagging. This is in comparison to top stitched seams where each stitch is exposed. Tuck stitched seams are also more water resistant than top stitched seams, again because the seam is concealed internally.

Tuck stitching attaches the lock-knit baffle fabric to a small fold in the shell material. Tuck stitching joins three layers of fabric making for a much stronger seam than top stitching that only joins two.