The warmest bag in Mountain Hardwears superlight down series, the Phantom 0 features top grade 800 fill down insulation, an efficient mummy cut & superlight fabrics to give a bag that shaves ounces & maximizes warmth. Tight 5 baffle spacing prevents cold spots, while face gasket, a tailored hood & insulated draft tube with ergonomic collar efficiently seals in warmth. Available in left hand zip only.