Katabatic Gear Flex 15 900

The Katabatic Gear Flex 15 900 reaches the same 15°F (-9°C) comfort rating as the 850fp version in the Flex line, but with 34 g less down — 451 g of 900-fill-power goose down versus 485 g of 850fp duck down — bringing total weight to 683 g. This is the practical case for paying more for higher fill power: less down needed for the same warmth. Materials are RDS- and bluesign-certified goose down inside a Pertex Quantum Eco ripstop shell, with continuous horizontal baffles preventing cold spots from down migration. Like the rest of the Flex series, it uses Katabatic's open-footbox construction rather than a sewn or zippered closure, letting it lie flatter in warmer conditions, with pad loops securing it directly to a sleeping pad. Packed volume is slightly larger than the 850fp version at 9.5 litres despite the lower fill weight, likely due to goose down's loft characteristics. Both a stuff sack and storage sack ship with it — a cold-leaning three-season quilt for hikers who want the Flex 15's warmth margin without duck down's weight penalty.