Two single bags side by side leave a cold seam down the middle, and whoever ends up on it knows about it by two in the morning.
The Lowlight Double opens flat and covers a roof top tent mattress corner to corner, so there is no seam and no gap. It is cut rectangular with no hood and no taper, because nothing about this bag is going on anybody's back and there is no reason to shave grams off it.
The fill is 650-fill-power down with a water-resistant shell, rated to 20°F, and the two-way zips mean one side can open without waking the other. It packs into a compression sack that fits in the tent when it closes.
