The North Face Fission
I have last year's model. For a 20 degree bag it sure…
Fill: Polarguard Delta
Temperature Rating: 20 Degrees Farenheight
I have last year's model. For a 20 degree bag it sure keeps me warm on below 20 degree nights mostly due to reduced size. Drawback: zipper is quite "sticky tricky". Recommend for any lightweight hikers in damp climates.
Here's what other sites are saying:
It doesn't take nuclear fission or fusion to keep you warm at night - The North Face's Fission sleeping bag is a toasty, synthetic insulated bag that cranks the heat with PrimaLoft Infinity insulation. An insulated draft tube prevents cold air from sneaking in when you don't want it, and when you do need to cool down, open up the 1/3-zipper and zippered footbox vents.
- Mountain Gear
When every ounce counts, the ultralight North Face Fission sheds weight without sacrificing comfort for warm-weather backcountry trips.
An ultralight twenty degree Climashield Neo bag for three season use.
Seasonal campers and backpackers sleep tight three seasons out of the year with the lightweight synthetic insulation of The North Face Fission Sleeping Bag. The Climashield Neo technology uses two different thicknesses of PrimaLoft Infinity insulation that are resilient, warm, and transfer water vapor out of the bag. A draft tube and fitted hood keep the cold out. During warmer nights out, a zip-vent footbox and 2/3-length zipper provide fresh air, and the vaulted footbox shape lets your feet stretch to your normal sleeping position. Glow in the dark zipper pulls are visible without a headlamp.