The Sea to Summit Women's Trek I Sleeping Bag is cut broader than a mummy bag to give you room to move. The side zipper + footbox zipper are great for ventilation and allow the Women's Trek I bag to be opened and used as a quilt %u2013 opening up a world of possibilities for camping and travel in warmer climes.Features: Down: ULTRA-DRYDown 650+ Loft 85% Down Cluster Premium Duck Down Women%u2019s specific cut: the Women%u2019s Trek is narrower in the shoulders but wider in the hip section than a unisex bag (to allow a woman to %u2018curl up%u2019 in her sleep without flattening the down at her knees or hips)Women%u2019s specific insulation: The Women%u2019s Trek features extra down and a layer of Thermolite in the bottom two baffles for extra warmth where it is neededLength/Zip: Regular - right zip %u2013 will zip to any unisex Trek, Latitude or Talus sleeping bag to form a snug cocoon for two peopleSeason ratings: Indoor, Summer, Spring, Autumn