Ascent AcI -4C Ultralight Down Sleeping Bag

About the Sea to Summit Ascent AcI - 4C

The Ascent Ac1 is the perfect backpacking sleeping bag, combining the warmth and comfort of down with a lighter weight.

Light, warm, and comfortable, the Ascent is the sleeping bag of choice for most adventures, most of the time. The design offers the perfect balance of comfort vs weight with more space than traditional mummy bags, yet still delivering the thermal efficiency you need when exploring above tree-line.

A Free-Flow triple-zip design ensures your sleeping bag retains maximum warmth and efficiency when needed and multiple ventilation options when it’s not. A half zip on the right side of the bag gives you freedom of movement for both arms and additional ventilation, and means the top third of the bag can be folded down as a mini quilt. A full-length, 2-way left side zip and separate foot zip transforms the bag into a quilt for warmer weather outings.

If it’s warmth you’re after, close the zips, pull the cord locks tight to drag everything in, and relax in luxurious comfort. The generous allocation of high-quality 750+ Loft down ensures great insulation, while oversized draft tubes prevent body heat from escaping for added heat retention. The paneled footbox and 3D hood make sure you’re not compressing the down when you’re trying to stay warm.

Vertical chest baffles ensure the down insulation remains in place. A side block baffle construction maintains the 60/40 fill ratio, keeping more down on the top of the bag for maximum insulation.

The Ascent Ac1 is crafted for fast-moving alpine hiking and trekking with a compact design and low pack-weight backed by Sea To Summit's high-quality design.