Cumulus Mysterious Traveller 500

The Cumulus Mysterious Traveller 500 departs from the goose-down Lite Line series in one key respect: it's filled with 500 g of 700-fill-power duck down rather than goose down. Duck down typically has a lower fill power than goose down of comparable quality, so the bag needs more fill weight to reach a given warmth level — here that's a manufacturer-rated comfort of 1 °C, limit -5 °C and an extreme rating of -21 °C, positioning it as a genuine three-season bag for shoulder-season mountain trips. Fill is distributed 55/45 between the upper and lower sections, concentrating insulation where the body loses more heat. Total weight is 910 g, packed to 26 × 18 cm — noticeably heavier and bulkier than the down-optimised Lite Line bags, a fair trade-off for the wider availability and typically lower cost of duck down. The shell is a 20-denier Pertex Quantum ripstop at 35 g/m² with DWR treatment, trapezoidal baffles, a 3D anatomical hood and a trapezoidal footbox for foot room. Regular size, unisex fit.