Klättermusen’s down products use Box Construction. This keeps the down evenly distributed using internal sidewalls, instead of penetrating seams.

Most down products on the market are sewn through the outer and inner fabric with a single seam, resulting in thousands of tiny holes letting wind pass through the material and eliminating much of the insulating effect of the down.

Box Construction creates a fully windproof layer that maximizes the insulating capabilities of goose down, resulting in down garments without cold spots or wind leaks. The Box Construction is combined with 800+ Fill Power down making it possible to achieve a superior thermal efficiency at a much lower weight than using conventional construction methods.