Mountain equipment glacier 1000 sleeping bag left zip for higher trekking peaks and those camping in the depths of winter this more generously sized bag offers oodles of warmth and protection features drilite loft tm ii outer shell is lightweight breathable and water resistant 996g of 90 10 pure duck down with a minimum fill power of 700 mountain fit is both spacious and thermally efficient trapezoid baffles and slanted box wall baffles mid level side seams 5 baffle anatomically s