World class, high quality down
Montbell's premium down comes from water fowl that live in regions with seasonal temperature extremes. The down balls from birds in such regions are characteristically much larger.
Large down balls hold more warm air, which translates to needing less down to provide exceptional warmth retention.
Lightweight yet warm
When compared by weight to lower quality down, an equal amount of premium down is loftier and has better warmth retaining properties.