Vango fuse 2 degrees sleeping bag the fuse sleeping bag is perfect for those all year round adventures it has a unique blend of hydrophobic down and 4t synthetic insulation giving the user all of the insulative properties of a down bag in a compact package resistant to wet conditions the insulite fusions interlinked insulation supports the down achieving superior loft more info box wall construction down filling is contained in box shaped baffles for maximum loft and to maintain an