This is an older model North Face Tundra -20F Polarguard (synthetic), Long Sleeping Bag for sale with accompanying storage bag. I originally bought it off a friend and have had it for 6 years used about 2 times each winter. Apparently he wrote a large "L" on the bag for Large as seen in the photos.
The loft has diminished a bit since ownership and this is what I've noticed and found the best way to describe it: In a bivy -10F and below the bag is very cold and need heavier additional layers, 0F the bag is chilly and you need some layers, 10F and up standard layering will do. In a Tent with other people any of these temperatures is fine with a light layering system.
Packability is best in a compression sack otherwise it may take up 1/4 of your pack and I'm not 100% sure on the weight.
Let me know if you have further questions